I have an unusual Parker 'D' grade 20 gauge made in 1917 with 'Parker Bros' inlayed in Gold on the bottom of the receiver. I understand that it is the only 'D' grade gun made with a gold inlay. It 'letters' with the gold inlay and was made as a gift from Parker Bros to E.I Dupont for use at his trap shooting school at Young's Million Dollar Pier in Atlantic City, New Jersey. There's a name and number stamped into the receiver - "F.B. Potts. No. 717". You can see it in the photo directly under the gold inlay. The stamping is crude... not factory. Maybe it was done at Dupont's trap shooting school. Does anyone have any idea what the name and number might signify? Thanks, Chris