I tinkered a little more with the car.
I cleaned up all the wiring that was on the floor of the passenger side.
One thing that was there was a 12v relay that takes power from the ignition (when I turn the key to ON) and connects 36 volts to the coil of the main contactor. That got moved to the back, right next to the contactor, and screwed down beside it. What do ya know, there are still wood components to the car.
I also removed the 72V pack voltage wire that ran through the car up to the controller power. I ran it through a different hole in the firewall (on the driver side) and tucked it away under the body panel. It still has a spade connection on it which I can manually disconnect for working on the controller.
I've had the horn out ever since I put in the heavy-duty radiator-position battery tray. I went and dug up the old (rusty) horn and re-installed it. It doesn't quite fit right with the battery there, so I had to bend it up on an angle.
Here you can see the adjustment screws on the controller
You pull these screws out and then adjust the potentiometer under it, then put the screw back in. After a couple of test runs up and down the street, I have decided to max out both current and throttle response. It makes the gas pedal a bit touchy, but it also gives me much improved acceleration.
I also FINALLY mounted the controller decent.
I had a short chunk of aluminum (one more nice spare part from Tom!) which reached nicely from the front battery tray tie-down rod, to the side of the car, where there is a tapped hole.
I drilled holes in both ends of the aluminum. The drivers-side end goes right over the threaded rod, and the passenger side goes over an L-bracket held into the side of the car with a bolt going into the existing threaded hole.
What's nice about this chunk of aluminum is that it has slots in it. I ran two short machine screws through the controller mounting holes into matching nuts slid into the track. Since the nuts are the exact same size as the track slot, they can slide, but not rotate. I just used a screwdriver to tighten the machine bolts down, once I had the controller in the position I wanted it.
Although the controller has never even been so much as warm, the aluminum the controller is mounted on should also work as a basic heat sink.
I also flipped the vacuum canister right-side up, blasted the ice out of it with a heat gun, and got the switch working again. The vacuum switch to run the pump was a great idea, but cold/water/ice are in issue in the winter. It freezes up and then gets stuck in an on or off position. It's more inconvenient than anything. If it's stuck off - no power brakes. If it's stuck on - the pump just keeps running (will probably eventually wear on it, and it's noisy)
Here's what it looks like under the hood right now.
I still have plenty more wire clean-up to do. I also want to have the vacuum pump mounted nice and solid, preferably inside an enclosure. Guess the ammeter shunt could go in there as well. Maybe a little box or something for the wound-up trailer wire harness to go in too.