I traded for a pristine (like new, no box) nickle 15-4 at a show. It doesn't have a pinned barrel and has the small logo under the cylinder latch. The SCSW says the non-pinned barrel became the 15-5. It doesn't say when the logo went from the side plate to the left side. I have seen 15-4s on the forum in both variations. It has a late 1982 serial #, I believe, 269K9**. So is it a 15-4, or a mismarked 15-5? I really don't think it's ever been shot, but I will probably remedy that before long.