I turns out I should have been more careful drilling the holes for the screws to attach the template to the body; they were two small and one of the screws broke off when I tried to extract it. I had to bend the thing and unscrew it w/ a pair of pliers:
For the rest of this project I'm sticking the template to the body w/ carpet tape. It's almost too strong for the job. I was worried the tape would pull chunks of mahogany out of the body when I pulled the template off of it.
I finished up the neck pocket today. The first thing I did clear away as much wood as I could using a Forstner bit in my drill press to save wear and tear on my router and bits. I don't have a proper table built yet so I ended up clamping the template I wasn't using to it and supporting the body w/ that as I worked on it. It turns out that there is indeed a very fine line before clever and stupid:
Worked like a charm (somewhat to my surprise). A Forstner bit, by the way, is sort of an improved version of spade bit. It drills wide holes w/ a relatively flat bottom. It looks almost like a router bit:
I set the depth and drilled away until I had most of the wood cleared. The depth gauge on my drill press isn't too accurate so I did a few practice holes on scrap and double checked w/ a small ruler to make sure I didn't drill too much. When I was done, it ended up like this:
From here it was a simple job to clean it out w/ a three-eighth inch straight router bit and the template following guide. I worked very slowly and carefully and only ended up w/ a few minor mistakes that are (hopefully) mostly cosmetic and will covered up when the neck is attached anyway:
Ultimately, the neck fit in a little less tightly than I'd hoped but it does take a nice picture. Not too shabby for a first go at it, I say:
I realized another mistake I made which was not making sure the edges of the template were completely square w/ its top. There was a bulge along the in the middle of the template's edge that held the neck tightly but the template follower followed the top of the template rather than the middle so I routed out more than expected. It's close enough for rock and roll though. I'd imagine it's only marginally less stable than a standard tele neck pocket (which doesn't have support on both sides) and once I get some finish on there, it should fit in even better. If worse comest to worse, I will just insert shims on either side of the neck to keep it from going back and forth. The depth of the pocket and the very end of the heel are right on so there's no reason it shouldn't be stable in the direction the strings pull on it, provided I get the holes drilled properly.