It doesn't have to be a Registered Magnum - any old Smith in good shape should do. Hand Ejector .38 special, etc. If you are uncertain about the date, e-mail me the serial number, model of gun, finish and barrel length. A photo would be really helpful. As a member of the SWCA, I can ask Roy Jinks to check on it, can usually get an answer within a week or so.
Many thanks!
John