I got your post, I was not trying to correct you. My point was a lot of people thought it was the 19s (including me), I have a bunch of K frames and that 15-2 was the first one I ever ran into. I never even noticed until I put a model 19 cylinder with a gas ring on the yoke and went hey that ain't right.
Evidently his 64-3 has the ring on cylinder. I have 2 19-3s and both are on the cylinder. It was a short lived experiment.
I wonder just how many guns total were built that way.