Due to this thread and many other related threads on various forums, I finally bought to plugs and installed them today. One in my 627 Pro and the other in my 586 L-Comp.
I took no photos but everyone can find pics as to how they look.
I bought them from here, although there are likely other sources or retailers of this same company's products:
S&W Lock Delete - ORIGINAL PRECISION
My installation issues.
The 627 Pro went well installing the plug. Unfortunately, my prior rear sight blade mod/replacement I did on this gun had the parts fall out, as the captured/staked on nut fell off somewhere at some time and the sight parts fell out right on my workbench. I must not have adequately staked the nut onto the adjustment screw. I already ordered replacement parts.
With the 586 L-Comp. It was just a bit more frustrating as I had trouble getting out the original "trident" lock retainer and launched the spring. I found the spring but it probably took me an hour more to do this gun. The replacement "trident" didn't quite fit as well but I stoned both sides of it as it either came a bit rough or I put a burr on it myself as, otherwise, the "trident" wouldn't fit into the frame's slot. This is a fairly small part, by the way.
Next, I could only get the plug in from the inner direction, whereas the plug on the 627 Pro would go in from either the outside or the inside. Putting the plug in from the inside was fine, however, as it's really just the reverse of the disassembly process.
For anyone who loses that little "trident" spring, a Glock firing pin safety spring could work, but it is just a bit larger than the lost S&W trident spring. As previously mentioned, I subsequently found the S&W spring on the floor and the Glock spring wasn't needed.