These gentlemen have put you on the right track. Lauderdale County and Moore County, Alabama, had numerous gunsmiths, including John Bull who moved there from Tennessee ca. 1823. David and Hiram Kennedy moved to Lauderdale County from North Carolina about 1820 and established a significant gun manufacturing operation with the likes of Calvin Key, Jacob Stutts, and Asa Richardson (rifles attributed to each of them are known). Research by the late Dan Wallace formed the basis for much that is known of Alabama gunmaking, and his research is used in Jerry Noble's books. You particularly want to get a copy of Jerry's first book "Notes on Southern Long Rifles " and, as mentioned above, his second book as well. Plus, you will enjoy talking to Jerry.
Also, if you can do so, come to the Tennessee Kentucky Rifle Show at the Museum of Appalachia on the 24th and 25th of this month. You will probably see an Alabama rifle or two on display there. Email me if you want to discuss that further.
Enjoy the pursuit!
Wayne Elliott