T prove that I actually get to do some guitar work sometimes here's a pic of a just finished project - Installing a Carvin 501B Active Bass Module in a 5 string fretless Samick owned by the bassplayer in our churches praise band.
The deal involved designing a new cavity using as much of the old one as was possible. I routed it using a pattern I had drawn on the computer and cut on a CNC router. The position of the controls was patterned also so they fit properly. Then the cavity was lined with copper, soldered, and the electronics, pickups, and battery were installed. This was a pretty easy alteration and was done because it was cheaper than a new set of pickups. The only thing missing from the middle is the post between the PCB's that is the mount for a single screw that holds the back on. Along with a fingerboard shaping and dressing, the whole project took about 8 hours over a couple of weeks. I had to go slow since this was someone elses baby. If it were mine it wouldn't be as flawless!!