Pretty cool. You drill a 5/16" hole on top then use this bit to drill from the back side. Tuners fit tight as I only drill deep enough for the base to fit in (about 3/8"). Nice... allows me to leave more wood in the headstock as well.
So these are not the tuners... but they work well enough to test fit. I am going to use Hipshot open back tuners.
Fitted the control cavity cover... what a pain. The thing decided to warp on me. I had to heat it and clamp it flat to get it to fit.
Rough fit the nut. I won't glue it in until I finish the fret dress.