The Patent 324 of 1870 is the J.Thomas patent,covering a single bite snap action, with top lever opening. [I recently reviewed on this forum a H.& H. Rook rifle built on this patent action], J.Thomas was a Birmingham gun maker. The proof marks are Birmingham black powder pre 1900. The 13 seen stamped on the barrels means that although chambered as a 12G. The barrels at the time of proof were bored 13 G.This is by no means uncommon.The T.Cook business is reviewed in the book "English Gunmakers",by De Witt Bailey and Douglas A.Nie. They give the last date of operation for the business as 1866. This is likely the last date that they were recorded as active in the trade directories of the day. The use of the 1870 Thomas patent action, shows that T.Cook continued in business at least until 1870.
