I wouldn't recommend calling the seller who told you it was military. How do sellers make up crap like that??? He is either uninformed or dishonest. Sorry, but my attitude is not good when people don't know when to shut their yap...
Your rifle was made in 1916. If it has a round barrel it's a 12-A. An octagon barrel means 12-C, but if it is chambered for 22 Short Only it's a gallery gun 12-B. The "D" is probably a proof/inspection stamp unless the rifle is engraved; then it would be a 12-D. I doubt that is the case.
12a Find at Houston Gun Show, year help please.
Re: 12a Find at Houston Gun Show, year help please.
I forgot to mention my usual warning. Standard Velocity ammo should be used; not modern Hi-Velocity...