Engine work aside, you're going to have a learning curve on the house electrics, appliances, expanding house battery capacity, new US standard shore power, maybe a fridge swap to something that runs efficiently on 12V, than also solar on the roof ( I put a 160 watt panel up)....the list goes on.
My JB500 is the same model as yours.
And mine came over with about 12K miles on 4/20, I got it on 9/20, been working on it since, planning on heading off in a month.
I'm not modifying the engine. Just going to go slow. Timing belt, balancer shift belt, all belts, pulleys, water pump were done when I got it as part of my purchase deal.
Issues with old rubber / plastic parts decayed from age pop up.
The gray water waste tank spigot broke apart the first time I worked it, had to drop the tank, cut a hole to fit a new, different unit , re-fiberglass the tank, get it back up etc etc....things like that just happen.
My front end is getting new ball joints, had to replace the Idler arm, the synthetic bushing in it had deterioration, gonna replace the rear leaf spring bushings, also age related deterioration, and look into a helper leaf to boost the rear up a couple inches, plus I had a custom rear trailer hitch fabricated to pull my motorcycle trailer.