I've had thoughts along the same lines on my '57, Tony. She was totally original, 110 volt hot water and refrigerator, compressed air water system, and no black tank. I'm going to try to keep the spirit of the original: keeping the Princess stove, hiding a modern fridge behind the original Marvel door, reusing the cabinets, and probably using a window air conditioner hiding in a cabinet so I don't have to mess up the roof line.
Wally improved his trailers all the time, though, so I'm going to make my renovation be part of me. Boondocking will be important for me too, so I'll definitely be cutting the outside metal to accommodate propane hot water and refrigeration. I'm strongly considering replacing some of my inside aluminum with baltic birch and some of the rest will be polished instead of the original Zolatone. Still going to clearly be a '57 Caravanner, though, whatever I do.
I think it's more important for those of us with really old trailers than newer ones to retain that original look, but I don't see why we can't make make some mods to suit the way we'll be using them today.
Most important thing, I think, is to get them back on the road and back in use camping.