Thanks a lot, guys. I'll take another look. I saw the hole you mention, but let me take another really close look at it and get back to you.

Again, really appreciate the help. Gambo, yes, I'm trying to be really careful not to lose the screws, including the set screw for the heating cartridge, that I've pulled out so far. I was working on the mount for my telescope awhile back, ended up with separate little containers for all the screws, and still managed to lose a couple of the little ones. I'm pretty convinced that those little M3 screws evaporate when exposed to air for too long. :-) "CA", you've come to my rescue again. Much appreciated.