I just posted new photo's guys. I removed the grips carefully and I didn't get a picture with the cylinder open. However, I looked from each angle and there is nothing in there either. I see no SN anywhere except wrote on the piece of paper which I no longer can make out actually. I seen the online Colt SN search but that does not help me as I can't make that out. Maybe someone that can enhance the picture with software can get the numbers off it. This is the first time I removed the grips since I originally brought it home just after dad passed back in 2005 so maybe 2006. That notebook paper is old as dirt! Please check out the new pictures to see if anything now helps to identify specifically what the heck this is. It is a 38 I can tell that for sure but I have never fired it. Tight and locks up great. Very tight!