Interesting.....
In American Firearms Makers by A. Merwyn Carey, there is a listing for an "H. Elwell, about 1770. Flintlock Kentucky rifle maker at Liverpool, Pa."
There is also a listing for "Fredric N. Barger, 1836-1881. Maker of percussion rifles and smoothbores, shop at Concord, Oh." There is a Concord township in Champaign County. Obviously the same fellow CurtJ identified, but while likely, it doesn't proof he is your FN Barger.
I have no clue as to the value, but would enjoy seeing pictures. Please post.
-Ron