Well, the planets were all in alignment today and I got several hours (!) of time to work on R2. After futzing around looking for suitable hole templates, I finally decided to bite the bullet and use the Dremel tool with the circle cutting attachment to cut the holoprojector holes.
I did a test cut on a scrap of Sintra to make sure the hole would be the right size. I then drilled a pilot hole in the center, fired up the Dremel, said a prayer, and then plunged in.
As it turned out, my anxiety was for naught. The Dremel tool made a perfect hole with very few plastic schnibbles to clean off the edge. I used a standard 1" hole cutting bit with my cordless drill for the PSI holes. Nice and smooth!
I got the rear logic display and one of the front logic displays cut out but by then I had to attend to the boys, who were in each other's business again. Big surprise.
Adventurous plan for this week: one more front logic to cut out. Sand the hole edges and prep the dome for painting. Glue in the HPs and logic displays. Glue the dome to the base ring. Prime.