Chris Hirsch casts flint lock kits from originals. Not sure how many locks he has patterns for at the moment, but it must be several dozen by now. Here's a couple pictures of him and some of his wares at the CLA convention in August.
I tried my hand at assembling a lock from a kit. Didn't work out too well. Couldn't get the frizzen hardened properly no matter what I did. Thought I had the hardening process down but it never would spark so I abandoned it, bought a ready made lock and kept the kit for spare parts.