Either one of the Chamber's Ketland locks would be fine although I believe I would grind off the point of the earlier Ketland to get a round tail{see below}.I have never seen an upper east Tennessee or for that matter any Tennessee rifle with a Germanic{Siler}lock. I did,however,once have a restocked Charles Bean the elder rifle with a squared off lock like the Chamber's late Ketland and a late Baxter Bean percussion rifle with a round tail lock. Check out the pair of silver mounted Baxter Bean pistols now in the Tennessee State Museum with the round tail Ketland lock and externals almost identical to the Chamber's late Ketland lock.This pair of pistols is illustrated in "Thoughts On The American Flintlock Pistol", PP.50-51
Tom Patton
Tom Patton