Made by Bill Mains, very unique 3" skinning blade - that blade shape seems to be one of his unique builds based on a design by Sid Bell. Sanbar stag handle, brass guard. "MAIN" is stamped into one side of the guard, and "62" on the other side.  There's a brass inlay in the butt that says "Mains Custom Knives, Buffalo NY". Vintage seems to be late 60s or early 70s when he was an engraver at Colt and Ithaca. M-2 high speed steel, Rockwell 63-ish. Looks to be mint - never carried, never sharpened. Original sheath, possibly buffalo hide.