On a 20 year old camper what's most important is its current condition rather than any "weak points" or "flaws" it may have had. It's made it this far, so how bad can those "weak points" possibly be?
If it's in good shape, everything works, no evidence of leaks, seems like it was well cared for, you like the layout, and the price is right, don't hesitate. Take care of it and it will last another 20 years.
Putting 10-ply tires on half ton trucks since aught-four.
