I am helping a friend with info on a 48-3 with the 8" barrel. It is a pinned/recessed 1975, but using my 4th Edition S&W book, the serial number is not listed I can see. It has me thinking as to whether it's a -2 to -3 transition model? The serial is 8k999 & change. The 48 -3 starts it seems at the 8k200xxx mark. The entry just above is a 6k number to an 8k, but that 8k entry ends before this model 48s serial starts. It lies in between the two somewhere. Is it made clearer in the 5th edition book maybe ? Where does the 48-3 8k999xx fall?