I have a Ball and Williams Ballard SN 13906. It has no Inspector or Sub Inspector markings. It is a carbine that falls within manufacture during the Civil War. What it does have, is an oval stamped or carved where the cartouche should be. Inside this oval is carved "5V or SV" (photo below). There is also "CSA" carved crudely in the stock as well. Is it possible that this is a Confederate Inspector Mark?