This "Les Paul type controls" mod is something I am also seriously considering for my H H Jackson. The "master volume/master tone" configuration is the only thing I don't like about the guitar. I'm thinking of removing the volume & tone pots, plugging the holes & drilling 4 new ones in the typical Les Paul layout. I need to make a template of the cavity first, to be sure it'll all fit, though the controls may all need to be tad closer together than on a Les Paul. Cheers
For me, I think redrilling new holes is a non-starter. Given the type of finish on the guitar, I don’t think I’d be able to refinish the area properly. So, I have to work with what I’ve got. I will be able to make the controls fit, but I’ll end up with an elongated parallelogram pattern for the knobs. It will help if I also switch to a quality mini pot, like a Bourns.
I find that I blend pickups so much with an H-H guitar that the single volume/tone is a little inhibiting.


