Still trying to find information to put at least a quarter year date on these guns. What I am looking for is guns with the patent dates of between Mar 20,'83 and July 13,'86, guns should have a serial number below 16656. Also if anyone has any serial numbers along with patent dates (3) I would appreciate them. There seems to be a conflict of interest between Brophy's book and John's findings on these guns. Hopefully with some assistance we can find out. I have few emails to the leaders, still waiting for a reply. Thanks.