My youngest brother saw a muzzle loader 1849 pistol in his Jr High library, so he made one.
He did not know about leaf springs. He used auto shoe brake springs from our garage in the locking mechanism.
Everything like this would be lost in 40 years, but our other brother recently found it in his basement full of junk.
I took his picture when he was a teeny bobber shooting, because it made so much smoke. He has more belly and less hair now.