Found and bought a pretty nice Model 15-1 at little local gun show today. Bluing about 90% (wear at normal high points) with a set of replacement Herret stocks as only detriment I can see. Serial number of K430xxx dates it to '60 or '61 I think. Probably paid all it is worth at $375, but was happy to find it as we don't see too many around here. Should be a good shooter and I may try my hand at converting the grips to "Jordan style" while searching for something closer to original. Thinking I will enjoy this 50+ year old iron. Looking at Wikipedia, the -1 engineering change only involved reversing the ejector rod threading (not a bad thing after having a Model 43 that needed rod tightened after every 10 cylinders fired!) otherwise just like a pre-M15. Am happy!

Congrats on a nice find !
The dash 1 revisions was a fairly short run as the new 3 screw 15-2 came out shortly after.

Your correct the 15-1 is also a 4 screw frame like the 15 (no dash) but has the new improved L hand thread ejector rod and cylinder , many have the letter "L" stamped on the cylinder so parts were not mixed up.

The majority shipped with diamond Magna grips, Diamond targets were an option and look good on Combat Masterpieces IMO.

Post some pics when you get a chance !

Warning: Model 15's will multiply in your safe. I think you got a good price mine have averaged right around $400.

Thanks for the additional information, Engine39guy. Am having a tough time posting images (keeps saying "upload failed") but am thinking I have to turn resolution down on camera or something. Not the easiest thing for a 65 year old, maybe I can get grandson to help me!
Have a set of smooth Target grips to try out maybe.

Have a pre-M14, Model 64,and a M60-4...not sure what kind of crossbreed I may end up with!
As I said, have not seen ANY Model 15s in a couple years (except here on the forum.)

I certainly would have paid that for it. I have a 67 no dash. (stainless 15) Good shooting gun. Got a 14-3 this year. Don't know why it took me so long. Enjoy your 15! Bob