With the "T. Davidson" lock plate from Cincinnati, Ohio, your rifle is very likely made by either Michael or Benjamin Sells, two brothers who were gun makers along the Ohio River. Michael Sells worked in Augusta, Bracken County, Kentucky from about 1830 to 1870, while younger brother Benjamin worked across the Ohio River in Georgetown, Brown County, Ohio from about 1835 to 1884. When you get the rifle, look closely for the first initial, and I bet it is either "M" or "B"...with Benjamin's work being a little more frequently seen. Benjamin was trained by his older brother Michael, so their work is somewhat similar. Shelby Gallien