Drew
Again thanks to all of you you responded to this post. I think I understand what a dolphin hammer is! I found out the world these old Purdey guns live in is pretty small. The picture you sent to me of an old Purdey left my house four days before your response to be returned to Steve Barnett. I decided that gun was not for me because it was not "original enough".
I hope that doesn't elitist. That gun was made in 1868 and had a replacement stock and sleeved barrels. It also had rebounding hammers which were quite rare in 1868. The Stanton patent was only issued a year or two before 1868. I suggest the locks may have been changed to rebounding hammers when the gun was totally restored in England. As I understand it many locks where changed to satisfy the US market. I found a gun that I think is totally original. I'll know for sure when I get the build data and the name of the original owner from Purdey. I'll attach photos of the gun I bought on my other post about "Purdey barrel marks" if I can figure how to do it! Again thanks to everyone who has helped me understand more about this fascinating old Purdey.
Bob