I'm working on the hand brake. The hinge in the top photo is part of the linkage, near the back driver's side wheel. I tried 'Rost Off' and a big hammer and can't get the thing to turn freely.
The hand brake ratchet is missing a couple of teeth. Must have spent some time in the NHL.
The pawl for the ratchet is missing. That's going to be tricky to design and build. It looks like getting the ratchet arm out would be a lot of work, so we'll probably have to measure and fit the pawl in place.