OK John, here’s another academic exercise... how about a Model 915 slide on a 2nd Gen frame? It Should work as it looks like the 915 is to the rest of the 3rd Gens as a Model 28 revolver is to a Model 27. They only came with fixed sights and single sided decocker, but otherwise look like they are the same. Do the internals interchange? I’ve read the appropriate section of SCSW, 4th ed, and that’s what I got out of it.

Froggie