Here is a partial list of products from HEINR. BORGWALDT, a company that operates out of Germany who describe themselves as a Manufacturer, Dealer, and Exporter of All Kinds of Tobacco Ingredients. I have also included the recommended amount to be applied in grams of product per 100 kg of tobacco. The document is from 1967 and can be found here https://www.industrydocumentslibrary.ucsf.edu/tobacco/docs/#id=npwc0101
Here is a link to their current website http://borgwaldt.hauni.com/en/company/facts-and-figures.html Something I found to be interesting is the multiple products that create the flavors we normally associate with the natural curing and processing of tobacco. For example, Latakia, Kentucky, Perique, Virginia, Dark Fired, Turkish, etc. There are even multiple products with the name Pipe Tobacco, presumably useful if you don't want to mix something on your own. The use of standardized, chemically pure flavors is the only way to ensure product consistency when creating a blend that is made over many years. While we may like to think of tobacco blending as we would think of making food in our kitchen, natural plant materials are too variable in quality to be of use in large scale manufacturing processes over a long term. I do not know how wide spread the use of these products are, and given the Cornell & Diehl Golden Days of Yore video that jvnshr posted it is clear that they are not always used, but considering that this business exists and has such an extensive catalog, someone must be using them. These products are assigned codes in the catalog that are different from the names listed here, and these codes do change with time. Woodsroad mentioned the use of codes in recipes and these may be for products similar to what is listed here. In addition, as flavors are dissolved in an alcohol solution before being applied to tobacco, it is an easy task to separate a blend into component leaf types by weight and analyze the toppings applied to each type by redissolving them in alcohol. The alcohol solution can provide the amount of every flavor additive used. I have not included many flavor products listed in the catalog, including ones labeled as American Blends. Look below and see if you can identify some familiar flavor profiles for blends you enjoy. I thought Tonka 322 sounded like a pleasant flavor. Perhaps Otto of Rose of Geranium 2419 is a component of what we call Lakeland essence. I can imagine Full Virginia Flake using a hint of Honey 1890 and Straight Virginia 2818.
I have a list of many plants that are used as the source for tobacco flavors, and may list them in the future as source for DIY folks. I will end with a general remark about Tonka and Deer Tongue. Both of these historically common tobacco ingredients have one thing in common, Coumarin. Coumarin contributes a sweet, creamy, vanilla like quality to products. It is of questionable safety, but is sometimes allowed in certain quantities depending on the country. Coumarin is often used instead of Tonka or Deer Tongue to achieve the same basic flavor, although substitutes are needed in countries that have banned it. I understand that cheap imitation, or Mexican vanilla contains, or did contain Coumarin, if you are looking for a source to try at home. While Coumarin is used as a blood thinner by prescription and as rat poison, under the name Warfarin, I would not use these sources.
Some Basic Tobacco Flavors
Almond 1361 (Strong, sweet), 13-30g/100 kg
Angelica 3011 (Rich, spicy), 100-120g/100 kg
Angelica 2542 (Similar to 3011, but non-alcoholic), 100-120g/100 kg
Anise 375 (Strong, intensely sweet), 30-50g/100 kg
Apple 2441 (Fresh fruity note), 100-120g/100kg
Apple 2740 (Full-bodied fruity), 100-120g/100kg
Apricot 1153 (Soft and sweet), 100-120g/100kg
Apricot 2318 (Sweet, aromatic), 80-100g/100kg
Apricot 2801 (Soft, fruity), 80-100g/100kg
Apricot 3300 (Rich Apricot-Kernel note), 100-150g/100kg
Banana 1741 (Intense, sweet), 80-100g/100kg
Blackberry 2381 (Sweet and fruity), 100-150g/100kg
Blackberry 3248 (Rich, sweet), 100-120g/100kg
Blackberry 3358 (Strong, aromatic), 100-120g/100kg
Caramel 2096 (Heavy, intense), 50-150g/100kg
Carob 1002 (Heavy St. John's Bread note), 100-200g/100kg
Carob 1605 (Rich St. John's Bread note), 100-200g/100kg
Cascarilla 2161 (Aromatic, spicy), 30-60g/100kg
Cascarilla 3234 (Spicy and woody), 100-200g/100kg
Cedarwood 1870 (Strong and balsamic), 30-50g/100kg
Cherry 2444 (Fresh, fruity), 100-120g/100kg
Cherry 2974 (Balsamic, aromatic), 100-120g/100kg
Cherry 3301 (Rich Cherry-Kernel note), 100-150g/100kg
Cherry, Wild 1221 (Sweet almondy Cherry character), 50-100g/100kg
Chocolate 2324 (Soft cocoa note), 100-150g/100kg
Chocolate 2916 (Slightly fruity), 80-100g/100kg
Chocolate, Cream 2397 (Rich, creamy Cocoa note), 50-100g/100kg
Chocolate, Cream 2411 (Soft and sweet), 50-100g/100kg
Chocolate, Ginger 1895 (Full-bodied Cocoa-Ginger note), 80-100g/100kg
Chocolate, Ginger Cream 1883 (Soft, sweet Cocoa-Ginger note), 80-100g/100kg
Cocoa 690 (Soft, aromatic), 50-150g/100kg
Cocoa 700 (Strong, sweet), 80-100g/100kg
Cocoa 1389 (Rich Cocoa-Vanilla note), 100-200g/100kg
Cocoa-Walnut 2708 (Strong, nutty Cocoa note), 80-100g/100kg
Coffee 1772 (Heavy, aromatic), 30-100g/100kg
Cola 834 (Fresh, spicy), 80-100g/100kg
Coriander 3591 (Balsamic Coriander-Clove note), 80-100g/100kg
Cinnamon 1043 (Heavy, somewhat balsamic), 50-100g/100kg
Date 2239 (Sweet, fruity), 1000-1500g/100kg
Deer Tongue 1841 (Heavy, aromatic), 100-120g/100kg
Deer Tongue 1032 (Heavy, sweet), 100-200g/100kg
Deer Tongue 1720 (Full-flavored, soft and sweet), 30-50g/kg
Deer Tongue 1732 (Strong and spicy), 100-200g/100kg
Deer Tongue 2247 (Fruity Deer Tongue-Tonka note), 80-100g/100kg
Deer Tongue 2359 (Full-bodied, spicy), 100-120g/100kg
Fig 668 (Sweet, intensely fruity), 100-200g/100kg
Fig 2015 (Mild, fruity), 500-800g/100kg
Fig 2040 (Strong, fruity), 100-150g/100kg
Fig 2459 (Fresh fruity and sweet), 200-300g/100kg
Fennel 2089 (Rich and strong), 80-100g/100kg
Havana 2434 (Spicy, woody, balsamic), 50-60g/100kg
Havana 3314 (Woody Cascarilla type note), 80-100g/100kg
Hazelnut 2523 (Fresh and sweet), 50-60g/100kg
Honey 1011 (Strong, slightly spicy), 50-100g/100kg
Honey 1528 (Soft sweet Honey-Tonka note), 150-200g/100kg
Honey 1541 (Floral Fennel-Honey character), 20-50g/100kg
Honey 1801 (Rich, balsamic), 30-40g/100kg
Honey 1890 (Sweet, floral Honey-Rose note), 50-60g/100kg
Honey 2000 (Soft, sweet), 500-700g/100kg
Honey 2341 (Soft and floral), 50-100g/100kg
Honey 2703 (Heavy-bodied, aromatic Honey note), 40-50g/100kg
Keora 2438 (Spicy, somewhat woody), 50-70 g/100kg
Kentucky 1750 (Full-bodied, smoky Fired-cured Tobacco note), 100-150g/100kg
Kentucky 2185 (Heavy, smoky, slightly fruity), 100-150g/100kg
Latakia 1752 (Spicy and smoky), 80-120g/100kg
Latakia 2148 (Soft Latakia-Tonka note), 100-120g/100kg
Latakia 2160 (Sweet, spicy), 100-120g/100kg
Latakia 2826 (Heavy-bodied, smoky), 100-200g/100kg
Latakia 3296 (Mild, smoky), 150-200g/100kg
Lavender 1840 (Fresh, strong), 10-50g/100kg
Licorice 2409 (Soft, somewhat spicy), 100-150g/100kg
Licorice 2518 (Mild and sweet), 50-100g/100kg
Malt 2103 (Heavy Caramel-like note), 800-1000g/100kg
Maple 287 (Intensely spicy), 100-200g/100kg
Maple 1084 (Soft, sweet, quite spicy), 100-300g/100kg
Maple 1203 (Heavy and sweet), 300-500g/100kg
Maple 1652 (Full-bodied, fruity), 50-100g/100kg
Maple 1774 (Sweet, slightly smoky), 100-150g/100kg
Maple 2036 (Rich, soft Maple note), 200-250g/100kg
Maple 2312 (Fruity, pleasantly spicy), 150-200g/100kg
Maple 2358 (Soft fruity and heavy), 150-200g/100kg
Maple 2389 (Quite fruity), 200-300g/100kg
Maple 2693 (Smooth, sweet and fruity), 120-150g/100kg
Maple 3306 (Soft fruity), 150-200g/100kg
Menthol 1495 (Full-bodied Menthol note), 100-300g/100kg
Menthol 1907 (Soft, minty), 200-300g/100kg
Menthol 2207 (Rich, minty), 100-200g/100kg
Menthol 2976 (Heavy and minty), 100-300g/100kg
Mint 1872 (Fresh, smooth Spearmint-like note), 100-300g/100kg
Mocca 1893 (Heavy, smooth Coffee note), 50-80g/100kg
Mocca 1904 (Mild, aromatic), 80-100g/100kg
Orange 2209 (Soft and sweet), 100-200g/100kg
Orange 2543 (Fresh fruity), 50-100g/100kg
Otto of Rose of Geranium 2419 (Heavy, sweet Geranium-Rose note), 30-50g/100kg
Raspberry 1782 (Extremely fruity), 80-100g/100kg
Peach 1171 (Rich, fruity), 100-150g/100kg
Peach 1794 (Intensely fruity), 50-60g/100kg
Peach 3356 (Strong and fruity), 100-120g/100kg
Peach 3357 (Full-bodied fruity), 80-120g/100kg
Pear 2008 (Full-bodied fruity), 100-120g/100kg
Perique 2153 (Slightly fruity and smoky), 100-120g/100kg
Plum 1140 (Fresh fruity, sweet), 100-150g/100kg
Plum 2705 (Full-bodied Plum note), 80-100g/100kg
Prune 2127 (Heavy), 100-150g/100kg
Prune 2412 (Smooth, aromatic), 80-100g/100kg
Rosemary 1900 (Fresh, aromatic), 20-50g/100kg
Rum 756 (Heavy and strong), 30-100g/100kg
Rum, Jamaica 2047 (Rich, aromatic, slightly fruity), 100-150g/100kg
Rum 2236 (Soft fruity, aromatic), 100-120g/100kg
Rum 2360 (Strong, slightly fruity), 100-120g/100kg
Rum 2424 (Smooth, fruity), 100-150g/100kg
Rum 2573 (Rich and strong), 50-100g/100kg
Sandalwood 1830 (Smooth and slightly balsamic), 20-30g/100kg
Spice Flavor 2443 (Strong herbal spiciness), 20-30g/100kg
Spice Flavor 2921 (Rich, spicy Gingerbread-like note), 100-150g/100kg
Strawberry 1650 (Full-bodied fruity), 40-50g/100kg
Sweet Flavor 559 (Sweet fruity and floral), 30-50g/100kg
Sweet Flavor 2137 (Soft, floral aromatic), 80-100g/100kg
Sweet Flavor 2138 (Strong, Caramel-like), 80-100g/100kg
Sweet Flavor 2139 (Rich Honey-Vanilla type note), 80-100g/100kg
Sweet Flavor 3309 (Floral, aromatic), 80-100g/100kg
Tamarind 2068 (Heavy fruity character), 150-250g/100kg
Tonka 322 (Smooth New Mown Hay note), 50-150g/100kg
Tonka 1040 (Fresh, floral), 100-120g/100kg
Tonka 1468 (Heavy and spicy), 20-40g/100kg
Tonka 1736 (Rich, strong), 80-100g/100kg
Tonka 2203 (Soft Tonka-Rum note), 1000-1500g/100kg
Tonka 2336 (Heavy and sweet), 50-100g/100kg
Tonka 2404 (Heavy, spicy), 20-40g/100kg
Tonka 2856 (Smooth, viscous extract-like note), 40-50g/100kg
Tonka 3308 (Soft, slightly fruity), 50-100g/100kg
Tonka 3350 (Fruity and balsamic), 500-700g/100kg
Turkish 3222 (Balsamic, floral), 150-200g/100kg
Vanilla 557 (Rich and strong), 20-50g/100kg
Vanilla 2213 (Strong, sweet), 20-50g/100kg
Vanilla 2226 (Soft and fruity), 150-200g/100kg
Vanilla 2345 (Soft and fruity), 150-200g/100kg
Virginia 666 (Heavy and spicy), 40-50g/100kg
Virginia 2070 (Heavy, floral spiciness), 50-100g/100kg
Virginia 2090 (Soft and floral), 50-150g/100kg
Virginia 2457 (Smooth Caramel-like sweetness), 80-100g/100kg
Virginia, Dark 2328 (Heavy Latakia-St. John's Bread type note), 80-100g/100kg
Virginia, Dark-Fired 2393 (Heavy and smoky), 150-300g/100kg
Virginia, Sweet 1817 (Fresh fruity), 10-50g/100kg
Walnut 2855 (Heavy and strong), 50-80g/100kg
Walnutwood 1800 (Heavy, balsamic), 30-50g/100kg
Walnutwood 3336 (Soft and balsamic), 50-100g/kg
Wine of Latakia 1471 (Strong, spicy), 500-1000g/100kg
Wine of Latakia 1472 (Soft and sweet), 1000-1500g/100kg
Wine of Latakia 1882 (Rich, somewhat fruity), 500-800g/100kg
Wine of Latakia 2146 (Heavy, fruity), 500-1000g/100kg
Wine of Latakia 3223 (Strong, winy fruitiness), 1000-2000g/100kg
Wine Prune 2994 (Soft fruity and winy), 500-1000g.100kg
Straight Virginia Flavor Compounds
Straight Virginia 327 (Fresh fruity Tonka-Caramel note), 100-200g/100kg
Straight Virginia 1871 (Soft, slightly sweet Tonka-like character), 300-500g/100kg
Straight Virginia 2052 (Fruity Caramel-Tonka note), 300-500g/100kg
Straight Virginia 2054 (Heavy, sweet Rum type note), 300-500g/100kg
Straight Virginia 2150 (Smooth Caramel-Deer Tongue character), 100-150g/100kg
Straight Virginia 2174 (Rich, sweet Tonka base type), 300-500g/100kg
Straight Virginia 2279 (Strong Banana-like fruitiness), 100-150g/100kg
Straight Virginia 2302 (Smooth Caramel-Deer Tongue character), 300-500g/100kg
Straight Virginia 2304 (Full-bodied, sweet Tonka-like character), 100-200g/100kg
Straight Virginia 2306 (Strong Tonka-Caramel base type), 100-200g/100kg
Straight Virginia 2522 (Rich Deer Tongue-Cocoa note), 80-100g/100kg
Straight Virginia 2818 (Soft Pear-Deer Tongue character), 100-150g/100kg
Straight Virginia 3320 (Sweet fruity Figs-Caramel character), 100-200g/100kg
Pipe Tobacco Flavor Compounds
Pipe Tobacco 1019 (Heavy and strong Maple-Tonka note), 100-200g/100kg
Pipe Tobacco 1685 (Full-bodied, balsamic, Prune character), 80-120g/100kg
Pipe Tobacco 1686 (Rich, fruity Balsam-Tonka note), 120-150g/100kg
Pipe Tobacco 1845 (Heavy-bodied Tonka-St. John's Bread note), 120-150g/100kg
Pipe Tobacco 1856 (Smooth, balsamic Rum-Deer Tongue type note), 120-150g/100kg
Pipe Tobacco 2212 (Rich, sweet fruity-like character), 200-300g/100kg
Pipe Tobacco 2305 (Soft fruity Deer Tongue-Coacoa base type), 100-200g/100kg
Pipe Tobacco 2372 (Heavy, sweet Tonka-Maple type note), 80-100g/100kg
Pipe Tobacco 2425 (Fruity and smoky Balsam-Rum note), 300-500g/100kg
Pipe Tobacco 2736 (Soft fruity, floral Vanilla-Tonka character), 100-200g/100kg
Pipe Tobacco 2739 (Soft Caramel-Balsam type note), 300-500g/100kg
Pipe Tobacco 2934 (Strong, fruity Tonka-Caramel note), 100-200g/100kg
Pipe Tobacco 3273 (Rich, sweet, Prune-like fruitiness), 200-300g/100kg
Pipe Tobacco 3275 (Smooth, fruity Caramel character), 300-400g/100kg