I need some accurate assistance: I have a nice original(??) Colt shoulder stock. Brass w/mustard patina finish. It has what appears to be Confederate stamping..at least on the top approx.1/4in. from the forward tip of the Bplate tang top. In deep tiny letters is stamped C.S.A....then on the R.side facing front towards rear of stock is stamped in 3/8in. numbers 12x and after that is fancy scroll capitol letters M.J(?).N. possible a cartouche(?)...heavy steel ring for saddle use. How do I determine if this is repro or possibly original.? I realize early examples were steel frame...Thanks.