1st time on this forum, as I just aquired an early 90's model Jayco popup. Not sure on the size but it's pretty big for a popup and it has dual axles. Its in so so shape, as in it looks worse than it is. A/C works, refrigerator works, water works, canvas is ok, roof dont leak (as far as i know)
Anyway my main concern is the 4 latches on the sides of the roof are rotting out. Not one latch works. I called 2 rv repair places and the best price was $1,000 to replace the roof, I also priced replacing the canvas and they said it was $650 just for labor to put it on.
If the roof isn't completely shot you may not need to replace the whole thing but with it being that old and all 4 sides rotted it doesn't sound good. In any event, should it be required the $1k for the roof sounds like a pretty fair price. But as long as your looking at replacement anyway you might get in there and poke around to determine the extend of rot. If for some reason its only in the vicinity of the latches you could probably rebuild those areas.
You can also order replacement canvas and do that yourself.
We just replaced both our roof and canvas in the past year. We bought the roof from the factory and picked it up ourselves ($800). We saved close to $600 shipping by picking it up ourselves, the factory is close to my sisters home. We just combined it with a visit. Borrowed a few friends and replaced it within an hour.
Last January we sent our canvas to Bear Creek Canvas and they sewed us a new one for $800. We got it put on a few weeks ago. If you are the least bit handy I would recommend replacing it yourself.
On a side note, if all of your side walls are rotting, there is a good change the whole top is rotting. But check it before you do anything. The side pieces would be a fairly easy replacement. We found out how bad ours was when I put a screwdriver all the way through the roof...easily. Check around the seams, that is where I found the moisture. It was extensive enough we decided to just replace the whole thing. It was expensive, but we now have $3600 into a trailer we will be able to use for years...and no payments! By the way, if you do buy a new roof, buy your latches at the same time. We ended up replacing our latches due to rust. We had to buy them from the factory. If we had known this when we got the roof we could have gotten them at the same time as the roof.