There should be little to no tension on the spring when the roof is all up (potentially the canvas needs to be removed to get there). The spring that I have seen was just a piece of steel rod about 1/3" thick with square ends. One end fits into the front scissor arm, the other one into the rear mounting bracket. When the roof is lowered, the spring is loaded by the roughly 1/4 rotation of the scissor arm. Which means that the max. torsion force is permanently applied to the rear brackets when the roof is in the lowered position.
The roof sheetmetal is glued on, at least I think it was with the Palomino. Different manufacturers may have different designs. The project was 10 years ago, so my memory is fading and I was not involved in all steps. The old roof was torn apart and discarded.
I helped to remove the old roof and put on the new one. We built a scaffolding around the camper (from actual aluminum scaffolding elements that my buddy had) and used ratchet straps to keep the roofs in place. It is an awkward position to work in, very tiring.
If you tear into it, you may not like what you find.