I have a friend who is has cancer and wants to sell a Win 94 in 38-40 that his great uncle used to herd cattle in west texas. His uncle gave it to him when his uncle was 80yrs old and that was some yrears back that he gave it to my friend. Now the stock is rough and the butt stock is loose but the metal is in very good shape and the bore believe it or not looks 90-95%. He wants to sell it but we don't know how to find out the age of this the rifle. Do you know how to find out?