hdhchf
No need to use repro parts to make a whole gun. I'll let you in on the BEST PLACE to get U.S. Martial musket parts, this includes all models of trap doors. Check out my freind Bil Osborne's shop, @ Lodgewood.com , he has all manner of parts, probably even a few original stocks, and especilly lock parts. I know from experience with muskets, the original lock parts "are the best". If you call them ask for Becky.
Good Luck Rebel Dave