I recently aquired what appears to be an older stainless steel .38 sw ctg with a sn of 538###. I've looked at several pictures but nothing matches this revolver.
First, if it's an older S&W and it's shiny, it's nickel finish, not stainless. AFAIK S&W has not made any factory SS revolvers chambered in .38S&W.
Second, S&W made 3 different models of .38S&W revolvers with different serial number ranges. We need to determine the model first. The candidates are:
1) .38/32 Terrier aka Model 32: 1-7/8" barrel, round butt, I-frame or J-frame (small) w/ 1-1/4" long 5-shot cylinder. (Just as a sidenote, I think it's amusing that the S&W Model 32 is not a .32 but rather a .38.
2) .38 Regulation Police aka Model 33: >3" barrel, I-frame or J-frame w/ 1-1/4" long 5-shot cylinder; older pre-numbered versions are easy to identify because of (a) distinctive wood stocks that cover lower half of backstrap (which has a small "shoulder" in it where the stocks fit) and (b) the words "Regulation Police" stamped into LH side of barrel. Later model-numbered guns don't have RP lettering and special stocks but should have square butt... except when they don't.
3) .38/200 British Service Revolver aka Victory Model: 4", 5", or 6" barrel, K-frame (medium) with 1-1/2" long 6-shot cylinder, should have "V" prefix in front of serial number.