Why don't you combine the two trades? You could probably make a decent living doing repair work on guitars. I know a guy that does that here for a few of the local shops. He's done all the work on my Ibanez.
Well, the repair would obviously be a portion of the music store. Plus I am going to be prototyping Microphone casings for a joint venture between my dad (a sound technician) and my uncle, and electronics genius. But that is still months if not years away.