I have a question on a 1863 shaprs carbine. I have had a few and some are stamped with three letter on the saddle ring plate and the barrel just before the breach and left side of barrel, and then single letters on various parts and a cartouch under the saddle ring bar on the wood. I have also seen several with no inspector stamps on the metal parts and cartouch stamps on the wood. Why would the wood have a cartouch and no inspector or sub inspector marks on the metal parts? A 1863 was made only during the war and I was not aware that any were made for private sale and the cartouch shows it was accepted by the US Gov. Any help on this appreciated