This rifle appears to be made by Benjamin Sells, Jr. He was the son of Benjamin Sells, Sr. of Union Co., PA and later Cleremont Co., OH. Benjamin, Jr. was born in 1815 and trained as a gunsmith by older brother Michael Sells of Bracken Co., KY just across the river, between 1830 and 1835. Benjamin, Jr. then returned back across the river to Ohio in 1835 and settled in Georgetown in Brown Co., where he worked until about 1870.
The lock attachment by a short screw from the front side of the lock plate into the barrel tang, was used by a few other gunsmiths in northern KY, and taken from British guns of the period. The trigger guard and stock profile, particularly through the wrist and lock area, are typical of Benjamin, Jr.'s work, altho I have not seen this particular patchbox on any of his guns. However, the box has the enclosed/captured lid of KY guns made in the central Bluegrass area and north to the Ohio River, as well as south into northern TN. Shelby Gallien