This thread is almost spooky my situation is so similar to Jim24.
I also had a LB in the late 80's, then switched to a Clod Buster, but I re-bought a LB in the early 90's with the exact same AirTronics Vector VT2P 75mhz. It's been sitting in storage for ~30 years and now for some (covid) reason, I'm obsessed with my LB again!
I also tried to revive my LB quick/easy/cheap, but that's not really the case. I also had similar issues with my radio twitching (dried-up foam & grossly corroded/misaligned transmitter battery terminals), so I just upgraded to a cheap Amazon 2.4Ghz model anyway. After removing the servo terminals from their old over-sized connector, I managed to fit them in the new transmitter in the right order get the LB alive again! But after seeing that manual speed controller, I'm also going to move to an ESC... and crazy ironically I was looking at the quicrun 1060 waterbok suggested on Amazon.ca HERE. A metal steering servo will inevitably follow
Unfortunately my LB was abused much more and I loaned my wheels to a friend ~30yrs ago (pretty sure squatters rights have kicked in), so rather than buy a few expensive-ish parts and spend a bunch of time re-building/cleaning/fixing, I just ordered a new Black Edition from some cheap online place in Hong Hong (we'll see if/how this turns out..). I'm going to drive my LB hard again, so I'll keep the old girl for parts if needed and I'm planning to have a separate "shelf queen" body and chrome rims anyway.
Like Jim24, I also have some old battery packs (some still working!), but it's very likely I also get sucked into a new 5000Mah battery for $40cad on Amazon too. Seems like fun driving for longer than 10min at a time now... LOL. I still have old 480T and Technigold motors, so after the stock build (with metal bearings & body mounts) it will be some gradual mods to improve it. But not too much... it still needs to be a classic out-of-control Lunch Box!