Wow John thanks, that is strange. Looking at the pics I see some major differences and actually considerably harder to make then the one Tom Burgess made. (the added difficulty would be in the area of cutting the hinge shape for the blade to rotate on. Perfect work for a wire cutter or a shape end mill) It may use the over the center pin concept which would not surprise me as being harder to operate. However, being stiff has it's advantages over the issue Fred was concerned about. Wish you could have gotten a pic from the top but I certainly do appreciate the 2 you posted. By chance you didn't get the name or info of the rifles current owner?