For american guns you can refer to Flaydermann's Guide to Antique gun prices for dates of production. For european guns you would have to refer to a number of books on the history of single shot rifles, of handguns, and of guns of various countries. If you just want a gun that you don't have to register, that is a slow and expensive process to collect them. If you are into collecting, they are books that you will ultimately want anyway.
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