I need to invest in me a copy of war baby 3. They are pricey but it seems to contain a lot of information not easily found anywhere else. Since you know the provenance, I would trust what I had in hand also. Does your Winchester have the M2 marking on the receiver ring? That's what Eddie, the OP originally wanted to see and me also haha was a picture of a Winchester M2 stamped carbine. The selector lever just being marked with an A and nothing else,may be an instance of where the first selector levers we're not marked with a makers code. Kind of like some early carbine parts not being marked.