Digging into this job, a half hour at a time, so I don't throw the whole thing through the window. After wiring up the harness, it appears that the switch has to be wired in the guitar. It won't fit in the hole in the pickup cavity, so I have to now cut the wires to the switch, install the switch, then wire the main harness to the 'tails' coming off the switch. BTW, the main electronics don't go through the pickup cavity- the channel to the main compartment is much too small. The main harness is certainly through the F holes.
A little bit at a time, every day...