That lock would be fine on a post 1800's gun. It is good to learn that you have all the parts. I have one of those on a pistol I made. The original mainspring was replaced with a small Siler mainspring. The Cochran's mainspring were known to be short lived. I like the lock very much as it is kind to flints. It does not have as much downward torque as a small Siler. The only drawback I find with the lock is that the sear is at a different position at each position of the cock. If the lock plate on mine hadn't been engraved by my friend Charlie Maggard, I would have replaced all the internals to that of a small Siler.