Gaston, George W
Private—Enlisted in Co. A, 10th Arkansas Cavalry, at Camden, Arkansas, January 23, 1863; present, February 29, 1864; born in Alabama, c1823; listed in Ouachita county 1860 census with wife Catherine; occupation farmer.

Could this actually be your man. The only 2nd Cavalry I know of served east of the Mississippi with Forrest.