[frizzen]

Well yeah, if any of us were that concerned about sharing ideas, we'd be those racers at the tracks who never pull the body off so you don't see their winning secrets.

I had a cunning plan: Start a toy conversion, document heavily in hopes someone is eventually inspired, get stuck, let them hopefully figure out the parts i stumbled at, and try to ride their coat tails to victory

Since some of yours crumbled, the Headlights are "chrome 1/2" hole plugs" many hardware stores carry them. I believe Doepke fire trucks used same size if you wanted new reproductions with the lens part cutout for adding lighting.

For the front end I had wondered with the expected final weight, if something like 1/14 Semi truck leaf helper-springs added on your wpls might help?
Maybe 4-link with something like fueltube or stack of O-rings acting as elastomer springs?
Cross drill a 4-link mount and hang from ballends for pendulum axle like original toy had?