Found a Union Soldier, Named Henry R Senour. Born about 1824.
Senour, Henry R. KY 12th Cavalry Regiment (UNION) I
◾12th Regiment, Kentucky Cavalry (Union)
Organized at Caseyville and Owensboro, Kentucky, November 17, 1862.
Returned to East Tennessee and duty at Sweetwater until August. Mustered out August 23, 1865.
Have not found anything saying he was a Gunsmith. But he must (could) have been from Kentucky.