The lock was made by Riddle, which I've seen referenced a few times I guess I'll look him up. It's a really nice gun, not like those ornate euro ones but built well .guessing it was a kind of midpriced gun there's some nice work on the barrel. If I remember correctly, my mom bought it for my dad for their first anniversary. So, that puts it in Aiken S.C. somewhere around 1955.