It seems nobody does have much on them.
From Braithwaite's book we learn that B Firman & Co. operated from Clifton Engineering Works, Curtis Street, Nottingham, distributing other makers' machines in the 1920s before becoming "manufacturing engineers engaged in fruits conversions and rebuilds" by 1931. In 1957, they were called S Firman & Co. (Nottingham) Ltd. and by 1960, Firman was an operator and caterer at Skegness.
They are best known for their bootleg versions of Mills Poinsettia, Roman Head and War Eagle. Notably, these are on old penny play, without jackpots and have decidedly rough cabinet castings (perhaps sand-cast from Mills originals). Presumably, they were made to revamp/rehouse earlier salvaged mechanisms? They also designed and built from scratch the only British bandit in the American style, namely, the Egyptian Bell, Sphinx or All Brit Bell Fruit. Again, I guess they made a cabinet only and fitted it with an American mechanism converted to old penny play. Finally, they made another bandit in a curious, brutal style all of their own which, judging by its rarity, was not a great seller. I believe they also invented a jackpot mechanism for retrofitting on pre-jackpot bandits.
Aside from bandits, Firman produced viewers, some kind of racing game and two rather tinny, metal-cased coin drop skill games: Pushapenny and Pushapenny Three Win with cigarette payout (example currently offered on ebay).
