Haven't had a chance to remove the spherical mirror yet. Probably won't get to it until this weekend.
This is actually my third projection set. I have an RCA 9-PC-41 and an RCA 648 PTK. I've got some pictures on the following threads.
http://www.videokarma.org/showthread.php?t=252908
http://www.videokarma.org/showthread.php?t=256597
I've done cabinet clean-ups on those two, and have started a restoration on the 9-PC-41, but it's taking a while since I still work full time (and then some). Right now, I'm in the clean up, preserve and display and enjoy mode for most of my sets. Once I retire in a few years, I'll be able to devote more time to the electrical restorations.