A very good paperback book specifically on Tennessee rifles is:
Gunmakers of Buffalo Valley & Greasy Cove, Dave Byrd. I believe you can find it for sale in the AmericanLongRiflesForums, I just got mine.
For Southern rifles in general there are four volumes, paperback, by Jerry Noble, Notes on Southern Longrifles. Call Jerry 309-582-2852, 414 N.E. 7th Ave, Aledo, Illinois. You'll have a good conversation, get current pricing & opinions.