I washed the covers on my 1988 (26 year old)
Scamp recently and the they turned out great. Except the the front sofa back/upper bunk cover that was coming apart anyway. I actually did more damage to it getting it off than I did washing it (cold water, gentle cycle, liquid detergent). Getting them back on was not too hard, take your time. Turn them inside out and pull over the cushion a little on each side and work them in. It was well worth the effort, I could not believe the pure dirt that came out of the cushions, not to mention they smell and feel a lot better.