Try "Crudgington & Baker Vol. 1&2"The British Shotgun"1850-1890. Its got 'Corking Info'Lots of Jolly Old Brit Inventions,Baker is the best with all those Patent's and his Vol 3 is near to Publication,(That the Word down at the Pub "The Queens Legs")..But I'm sure Michael Petrov will have the answer before we know it!! (By the way MP. many thanks for the James Woodward Pat. Drawing. I have framed it with the "Grip")....Slow day in the Workshop!!)cc/dt