There are numerous sources. One of my dealer friends who I bought mine from turned me on to (and I subsequently purchased) the publication "American Thunder - Military Thompson Submachine Guns" by Frank Iannamico. On page 380 there is an Auto-Ordnance Corporation, Williams Lane, West Hurley, New York list of the serial numbers and correlating dates of manufacture for West Hurley 1928 Thompson submachine guns produced between 1975 and 1992 as well as the special edition commemoratives which were manufactured by Auto-Ordnance: WWII Thompson Commemorative (85 made), Korean War Thompson Commemorative (145 made), and Vietnam Commemoratives (17 made). Similar and other lists are published in other books (interestingly also by Frank Iannamico) such as "United States Submachine Guns - From the American 180 to the ZX-7" on page 322. Hope that helps. I really like yours in the original box!