Leaky roof, sell as is or try to repair?

I'd check if you can file a water damage claim with insurance. Chances are slim, but if they do cover it, the rig likely will be totaled.

I do think it is good to sell it "as is" with the damage mentioned. Here in Texas, there are those who will buy a water damaged rig, haul it to their property, throw a tarp over it, and use it for a hunting cabin.