Bob sent me an update on his progress converting the car to lithium batteries (sorry it took so long to post it, Bob):
I found a pair of rear trunk torsion bars on ebay. To install them, I needed to split the rear battery box and remove the rear half. Because I had the batteries out, I decided it was time to get lithium. I decided that 40 cells would have nearly the same voltage as the 20 lead batteries. I ordered from Calib in Pomona and after a little wait, they were delivered from their stock. They were in three boxes on a pallet, and the UPS driver moved them with his manual fork lift right to the rear of Silver II. Back to the torsion bars. Installation requires two tools; a pry bar and a close-fitting pipe. The hinge is first removed and the pry bar is used to bend the spring to the rear under the corner of the engine cover. The pipe then holds the end of the spring with an assist of block of wood leaning against the underside of the corner of the engine cover. The hinge can be easily reinstalled. This is a one man job with the right tools. It is nice to be able to open and close the rear trunk without a broomstick. The saddle bag boxes are no longer needed so I have a full trunk to use.
I will include a few pictures of the lithium installation. Calib sent me the wrong hardware so I can't complete the wiring. One picture shows how I used the copper strap, modified, to terminate each box.