Bud - Russell Bean is the first of the Bean family that is documented to have worked as a gunsmith. He was a son of William Bean, who was one of the first settlers in East Tennessee and founder of Bean's station. There are stories of some of the older generations of the Beans being gunsmiths, including William, but to my knowledge it is still undocumented. Anyway, Russell was an interesting character - grew up fighting Indians by the time he was a teenager and apparently had a violent temper. Apparently he was a contemporary and well known to Andrew Jackson. I have heard of one surviving rifle signed by him - there may be others I am not aware of. I have never seen it, but I think it is dated in the 1790s but there is some uncertainty as to whether or not it is a barrel from an early piece by him, that was later restocked in the East Tennessee style that is believed to have became popular just a bit later, i.e. the banana patchbox, etc. But we really don't know exactly what the early rifles made in East Tennessee in the 1700s looked like, so who knows when the style actually first appeared?
Baxter was his son - born 1799 and died in the 1850s, and one of the best known makers of the what most think of as the classic style of East Tennessee rifle that seems to have appeared by around the 1820s.
Another one of the relatively early Tennessee gunmaking family were the Bulls (John and Elisha. They were intermarried with the Beans if I am not mistaken.
Jerry Noble's 4 volume set is the best thing out there on the mountain rifles. Someone gave his contact info above. Volume 1 has the most detailed info on the Beans and the Bulls.
"Wallace" is Wallace Gusler, a well known gunmaker, author, and expert in many things related to the American longrifle. His articles from "Muzzle Blasts" magazine in the past 5 or 6 years would be of interest to you.
Good luck
Guy