Jim Chambers, flintlocks.com, has a $5 catalog, if you like paper.
I just received two of his Siler pattern locks, one full size, other small Siler, with brass plates. Spark extremely well, beautifully put together. Delivery was in four days, not months. He has, of course, kits and some assorted parts, as well as that fine German book on Jaegers & an English translation of the text.
As I get back into my shop after long absence I've sort of become a "Lock Collector", looking for something that actually sparks, is well put together & with no internal design innovations. Have locks from five different sources. Still awaiting delivery of a small Ditchburn "J.P. Beck" lock, but so far Chambers' stuff is the best (Bob Roller's also finely machined wrought internals).
(Nice to see a lock with the mainspring properly installed so that it does not drag on the plate).