I've coated the overlay with glue, and I can see my marks to line up the overlay in the right position. I'll take my small knife and stab right through a bridge pin hole to hold the overlay in position:
See? Set at an angle the knife holds the plate nicely so I have both hands free to start clamping:
Well, that's about it. I'm clamping this plate firmly against a 1/2" x 2" steel bar I keep around for just this sort of thing:
I have masking tape under the steel to keep it from sticking in case any glue comes up through the holes.
I have confidence that the new bridge won't crack from folding at the line of the pin holes. No telling what other troubles this guitar might see in the future, though!
Here's a final fisheye look through the INSIGHT camera:
The overlay went on well, and I backed it up with a scrap of hardwood when I drilled the holes so there's no chipping. Why don't the factories do that?