I've been trying to trick customers into paying me to do this (good guinea pigs are hard to find these days!), and no takers sofar. I couldn't wait any longer so I "stayed after school" today and did it to a little project gun of my own. This is one that gets about an average of 2-3 hours' work a year done to it. Gawd, I'd better call in sick a few days this winter and get it done! Anyway, pics to follow, but instead of milling a dovetail through, I took the dovetails off the sight leaving just a rectangular lug protruding from the bottom, and milled a matching pocket in the slide. The whole sight is slightly narrowed, to match the width of the flat on the slide, which is as per usual to about the depth of the original dovetail. The sight is a light press fit into its pocket. By this time tomorrow there should be two .078 or maybe .093 pins holding it in. They will be in holes starting under the firing pin stop, and running forward, through the sight's underlug and then again into slide metal. Although this is meant to be solid, crash-proof and permanent, and although I hate blind pin holes, I will make them about a .001 slip fit, set them in anti-sieze compound, and tap the ends 2-56 so that they can be pulled. Or I might just be able to angle them up a tad so they break out into a dimple milled in the slide say 3/8 forward of the the rear sight, so that they can be tapped out. The holes would be stepped so that the pins can't come out forward, and they will of course be held at the rear by the FP stop. Yeah, that's it! Once the pins are out, the sight can be jacked out of its pocket by the original set-screw.
I have it set in the pocket now and it looks vewy vewy sanitawy.
Crap. I should'na posted this. Now I gotta go back out and work on it some more. I hate it when I do this to myself!