Good old Bob Kern,
I would have to say he probably saved our lives back there in the late 60's early 70's.
Some of the junk we were trying to build guns from while in high school. And we were allowed back then to build guns in high school.
Anyway, as I remember it Bob invented that lock, and you might notice how similar it is to a TC, which the story was he never made a dime from. Got that from Mary his daughter.
Bob ran "18th Century Hardware" there in Ligonier, along with the gun shop and a casting facility. I have a few of his trigger gds as well as a bett plate.
He looked a lot like Buffalo Bill. Years after we thought he had passed I met his daughter at the old shop to try and buy some parts. The roof was half fell in leaking, everything was rusted, barrels, locks, bins full of all kinds of parts. I think I bought a good hand forged hawk from her. Anyway when leaving she had to get change from the house and behold, there was Bon in a hospital bed. Didn't know anyone. And I think missing both legs as I recal.
Bad way to go. I'd say that was early 80's? Maybe later.
He was a pioneer in this area.