Hi oldguy,
There's not much online about Sommer, but this came up about a year and a half ago and I was able to dig up a bit on their early history. Here's what I wrote then.
The founder of the brand, Jean Florian Sommer, was born in Bielsko-Biala, Poland on May 12, 1829. Biala is in Silesia, very near what is now the border between the Czech Republic and Slovakia (on the northern, or Polish side). If you google it you can easily place it on a map. Jean's father, Florian Sommer, was a butcher. At some point Jean trekked across a large stretch of middle-europe and wound up in Paris, whether with his parents or on his own is unknown to me. He had certainly arrived by the spring of 1859 since he married a French girl there on April 25th. Later that same year he formed a company with two other men: Viney, Sommer et Hamm. Together they pursued a business in smokers articles, and also in 1859 apparently originated or obtained the rights to a patent for an improved tobacco pipe (I have a detailed description of the patent claims if you're interested). At any rate Viney, Sommer et Hamm (singly and as a company) don't appear in any of the almanacs I consulted until 1860, when they are listed as operating at Montmorency 19. By the next year's edition, in 1861, Viney is gone and the business is styled Sommer et Hamm; still at Montmorency 19, but with a second location at passage Mires 13 et 15. Interestingly enough, Mires was, two years later, renamed the "passage des Princes".
It wasn't long before Hamm too disappeared. The business is called Sommer et Hamm in 1861 and 1862, but by 1863 it is simply styled Sommer (J), with a sole location at passage des Princes 13 & 15. Jean continued to keep the business in his name, and at the same address, for almost thirty years (although he did later expand the operation to include 11 as well as 13 & 15 in the passage des Princes). In either 1892 or 1893 the business is still called J. Sommer, but in parentheses is added the phrase "Sommer Freres succ". Here I should point out that Jean and his wife (Leonie Louise Devarenne, born in 1840) had eight children: four boys and four girls. One of the boys died in infancy and one became an engineer, but the remaining two boys entered their father's business, becoming the "Sommer Freres" referred to above. These men were Edmund Henri Jean Sommer (b. 1860), and Louis Victor Sommer (b. 1863). Here the trail grows murky. I know their father Jean died in September of 1910, but he had presumably ceded the business to his sons almost twenty years earlier when it was renamed. I'm unsure when the sons died, or whether they in turn had sons to carry on the business after them. What I can tell you for sure is that the business continued to be called Sommer Freres at least through 1938.
Which brings me to another minor point. At least several of the few facts out there about Sommer are false. I think some of the names attributed to the business are wrong and represent different businesses entirely (Au Pacha would be one example), and I suspect the 1925 date for the catalog on the web is incorrect (if you've seen it, note the language on the front which suggests the brand is a century old, and claims an 1855 foundation date; this would place the catalog in the mid to late 1950s). For that matter if Sommer was in Paris and making pipes in 1855 it wasn't as an independent business; certainly he doesn't appear in the almanacs of the 1850s. The first time I've found him, so far, is paired with Viney and Hamm in 1860.
I know this only covers the 19th and early 20th centuries, but thought it might be of interest to know a bit more about the men who established and built the business that produced your pipe.
Rgds,
Jon
