Well...a little progess.
When I picked up my bus the headlights, tail lights, brake lights, and turn signals worked but not the marker lights. Also most of the switches on the overhead main panel didn't do anything...so no window fans, heater fans, defroster fans, etc would run.
I started with the marker lights first since it's hard to dirve without them if it's anything but broad daylight. It was an easy wire trace to a large (2" diameter) solenoid. Hmmm...the bakelite nose piece with the terminals on it was dangling in front of the metal body of the solenoid.
I suspect that when the video camera equipment came out that a mechanic removed the power wires to it (most likely coming from the solenoid) and put so much pressure on the nuts on the terminals that he broke off the bakelite end.
The solenoid still had a very readable sticker on it so I chased it down on the Internet and ordered a replacement (about '$28'). I installed it yesterday and lo and behold everything on the main switch panel came to life! And more amazingly everything the switches control works! Even the light monitor on the far left of the panel (which is a depiction of the front end and rear end of the bus with little indicator lights for all the real light positions) does its thing.
So at least one item on the conversion list has a checkmark next to it.
I also got my new Washington State motorhome plates installed yesterday. I wanted to get my wife Shelley out in the bus since she'd never been in it so we hopped aboard and headed down the road. She was as pleased about the sound level and ride as I am and she loves the visibility out those massive front windows. I pulled into a large parking lot after we had been on the highway a few miles and asked her if she'd try driving. She used to be my co-dirver when we owned our semi-truck so she's not a stranger to large vehicles but that was many moons ago and she always declined to drive our Blue Bird (and never has). To my surprise she said "sure" so we swapped seats, I gave her a run down on controls and operation (yes, honey, you have to press and hold those little round foot swtiches for the turn signals), and off we went. She did great and actually enjoyed it, this bus is a real joy to drive and quite easy to handle around town. I don't think she'll use it to go for groceries or to commute to work (her normal vehicle is a Jeep Wrangler...just a bit shorter!) but she likes it well enough I'll have a co-driver to swap off with while we're on the road. Yes!