I just received today this model 15-3 purchased in an auction last weekend. It is a typical PD gun, shot very little and carried a lot. The bore and cylinders are mirror bright, and the action is tight. It has finish issues, and I may have found one to send out for refinishing. Note the S.C.P.D. on the left frame. It has a target hammer and trigger.

The serial number is 8K13390, which I think makes it a 1975?

That would make a good shooter as is, but I understand the urge to refinish.