Here are the ones worth knowing (London): Purdey, H&H, Boss, Atkin, Beesley, Churchill.
Birmingham: Powell and Westley Richards.
Screw the rest.
PS. The best English shotgun was Woodward Vertical Gun.
Vertical Gun=insanely expensive O/U shotgun

It makes me feel like vomiting and passing loose stools, but $900 G.E. Lewis BLNE keeper grade (one with Birmingham proof marks not one of the Belgian POS) is far superior to my Sterlingworth ejector.