Samuel Glover of Tennessee's Sullivan County made a similar rifle. The stock opposite of the lockplate has a similar shape as does the escutcheon that secures the lock screw. However, the forearm is different and toe line is straight and not fishbelly shaped (or is that camera angle?). The trigger guard is different but a lot of times those were salvaged from other guns. Glover also had a cheekpiece. See page 112 of Jerry Noble's Notes on Southern Long Rifles, Vol. 2. From James B. Whisker's Gunsmiths and Allied Tradesmen of Tennessee, pages 34-35: Samuel Glover was born in 1830 and was a gunsmith from 1860-89 near Bluff City. He may have been associated with John Glover of Johnson City. Samuel was married to Elizabeth (born Eliza Pile of Beaver Creek Post Office of VA).
From David Byrd's East Tennessee Hog Rifles, Byrd puts Glover's birthyear as 1827 and year of death as 1912. Most of his rifles used sideplates and often installed patch boxes in his rifles. During the Civil War Glover was in the Confederate Army and rose to the rank of sergeant. He is buried in Blountville, TN. See page 57 (and illustrations up to page 66).
Rueben Luster (see Byrd) also carved some stocks relief panel like yours, but no escutcheon is seen (see page 101). Christopher J. McInturff used a similar upside down escutcheon, but the relief panel in more round. Ditto with Squire Runion (see Byrd age 135-138).
It is noteworthy that the relief panel is cut off near the wrist. This is unusual.
The above is not a positive identification of your rifle. More research is required. If you ever get to Woodbury, KY, you should show it to Hershel House and ask for his opinion. BTW, do not do any restoration on the stock. It's took early for that.