For what it's worth, when I took the cushions for my '84
scamp in to the upholstery shop, I told them I wanted new foam. The guy pulled a cover off, and said "no you don't, this is excellent foam. My stuff isn't any better. We'll steam clean it, and the collapsed cells puff right up."
He had quoted me $4-500 for foam right before he looked at it, so I was pretty happy he was honest.