You may have to put tires on it if the ones that are on there are too old.
I've had a few of these older units and if you are handy you can get use out of them. Don't let people scare you away but, be prepared to do some maintenance.
And, it depends on what sort of camping you want to do. If the gas / electric fridge is bad, or goes bad, and you are always going to places where you can plug in you can replace it with a small apartment type house fridge. If the furnace is bad and you always go to places where you plug in you can use a electric space heater.
But, as stated by the other members makes sure the roof is in good shape and there is no leaks. If you have to start rebuilding structure that is difficult and expensive.