And there's actually a lot more to say about SELM.
As papipeguy says, FC&G is indeed still in business, but they got out of tobacco a long time ago; towards the end of its run SELM was handled by G A Georgopulo & Co. The important point is that FC&G was only the U.S. distributor of State Express London Mixture (SELM); it was actually made (theoretically) by Ardath Tobacco.
There is info readily available online about Ardath (much of it wrong or misleading), but in a fairly small nutshell what later became Ardath Tobacco Company, Ltd. was founded by Albert Levy in 1895. He was joined by a partner, Barnett S. Gluckstein, in 1903. In a complex set of transactions apparently triggered by his desire to retire, in January of 1926 Gluckstein sold his shares "to a financial house in the City" and a holding company was created which held all the outstanding shares (Gluckstein's and Levy's) of Ardath. At the time it was coyly announced that British American Tobacco Company Ltd. (BAT) had acquired an "interest" in this new holding entity, and a collaboration in overseas markets was to begin immediately. Levy, who remained as head of the company, announced that despite BAT's interest, the business of Ardath would be "carried on independently, exactly the same as before". Half a year later it became clear that the new holding company ("Universal Tobacco Company") was in reality controlled and managed by BAT, and Ardath had become in essence a subsidiary. The long sad litany of events Ardath suffered under its new master, including the eventual outsourcing of its manufacturing and closure of its factories, is wholly irrelevant to the story of SELM. Likewise the convoluted relationship between BAT, Imperial, and what remained of Ardath's brands and the geographic rights thereto.
More to the point, by the time SELM came on the stage in the late 1960s Ardath had been a creature of BAT for generations, and what remained of the original company was apparently mostly a collection of brand names (along with a distribution function tacked on later). By then State Express, originally a cigarette brand trademarked by Ardath in 1896, was one of the largest assets left over from the Ardath acquisition, and had been exploited over time through a series of brand extensions and entries into international markets. SELM, a new pipe tobacco based on the marque, was developed in the mid-1960s. It was then trademarked in a variety of countries, including Canada (March 20, 1967), Australia (April 21, 1967), the U.S. (April 4, 1968), Germany (March 30, 1969), and Kenya (1970). It was advertised for sale in the US by the end of 1968. Internal company documents make it clear, however, that despite the various international trademark filings the blend was "created largely with the U.S. market in mind".
As far as I can tell SELM was only ever available in 2 ounce (from launch until about 1972-73) and 50 gram (1972-73 onward) rectangular tins. The product was considered to be successful enough that two expansions were considered: a) introduction into the UK (per documents dating to late 1974), and b) development of a cigarette incorporating SELM tobacco. It’s not entirely clear to me whether either ever got off the ground.
SELM was manufactured by the Liverpool branch of BAT. As mentioned the tins included two different varieties of tobacco leaves laid crossways over the mixture; and on top of the gold wrapping protecting the tobacco a small folded booklet describing the blend was enclosed. Each tin also had a British penny affixed to the bottom to be used in opening it. As my dad would have said, packaging is marketing. Luckily the sizzle had a fair amount of steak underneath, and the tobacco was (and is) terrific. The actual “recipe” consisted of 35% Virginia flue cured (i.e. Bright), 25% Orientals (i.e. Turkish), and 40% Latakia. The manufacturing process is also known, but too lengthy to summarize here.
Interestingly enough, the maker of SELM had a more limited view of shelf life then we do. Internal documents state that mixtures in general “Should be smoked as soon as possible for maximum taste. Tendency after three months to noticeable loss of flavour. Loss of colour in ‘Brights’ increasingly noticeable after three months”. All I can say is that I had some from a tin about 44 years old a few weeks ago and it was fantastic. If what I tried was really greatly diminished by the passage of time I can only imagine what this blend was like when fresh.
I should add SELM had a run of a bit over two decades. It was withdrawn from production sometime between 1989-1992: SELM appears in the 1988 RTDA almanac, but the US trademark was allowed to expire on November 3, 1992. It remains possible that the blend continued to be available in other countries thereafter, but given the importance of the US market to the brand that seems unlikely.