I think Ben has all the skills and tools to build, most, of an electric guitar. The electronics are trivial compared to building a computer and the body can be created on the CNC machine. The one thing I would not recommend for the first build is the neck, just buy a neck. In fact I have a neck he can use and almost all the other parts he could want. If a guitar is too simple, one could go for adding on board effects, fuzz, boost, dirt etc. which are also simple circuitry compared to hand wiring a computer. Some parts could be laser cut or engraved and there would be lots of opportunity to be creative with the body and the headstock.