I have been trying to find information on my revolver. I have been looking at different sites that list ways to date and identify but none have the particular serial number I have. On the bottom of the frame under the grips and behind the cylinder arm it is listed as AWA75xx MOD 67-1. It is a 38 S&W SPECIAL CTG. 4 inch barrel in stainless steal. I would like to know more about it and if it would be possible for a Smith to put a Heavy or Bull barrel on it.