Depending on your skills and budget it might be doable. I would be leery about any long trips but for local trips at first it might work.
Be aware that any RV requires a lot of maintenance. Old RVs require even more work. You will spend a lot of time working on the rig but the advantage is that you will learn a lot for a small initial investment. It might be a real diamond in the rough.
Mileage will be between 6 and 8 mpg.
I say do it! Buy it and use it at camp driveway first. Check out all the systems at home, not on the road.
For safety install new smoke, LPG, and CO detectors. Probably needs new tires and they aren't cheap. I think the age rule is ten years for motor home tires and 6 years for trailer tires.
