In reference to the question regarding fit and function: My gunsmith had to take over the installation project, once it became clear to me that the fit wasn't exactly...drop in!
He carried on some conversations with Ron Powers himself, and ended up having to file off some material from the grip frame.
All is well now, and the half cock capability is a hoot (not used to that on a Ruger)!
Hate to admit it....but this thing has STILL not been fired!
Plenty of 45 ACP on hand, just need some time!
(full range report to follow)