Jayco Winders and bits

I done a fair few in my years and most important would be servicing the wind up mechanism. Park your camper somewhere you can hang the roof up and take the wind up legs apart. They have springs inside who run in grease and collect dust over the years. Check the little guide wheels for the wires and the wires itself.
If you want to keep the camper and do some off road stuff fitting a sub-chassis is a good idea. I used to make a frame out of 75mmX50mm RHS and cut off the old spring hangers. Refitting them under the new frame. This makes the hole unit stronger and you get 3 inches more ground clearance.
Have fun with your project.

Reiner