Tap,
Bummer about the fuse. But, you really have not done alot of work. Trying to get a slight warp out with a heat iron may work but over time in the sun I bet the warp will come back. You may try removing the sheeting from the side finished last and re sheeting being more careful to put weight on the fuse to keep it flat until dry then see how it looks. If any question just start over. Good luck, Pete