For my friend, Drew Hause. On August 11, 1904, A.S. Birdsong ordered a D Grade 20 gauge Parker with 29" Titanic Steel barrels bored "Improved Cylinder and Three Quarter" chokes. The serial number is 128,592. This is the first mention of improved cylinder I have found. It shouldn't be a hard gun to identify if you run across it at a gun show. In my opinion, the customer named this choke because Parker Brothers did not normally use this terminology. Bill Murphy