It appears to me to only be gel-cote degradation. If it were me I would sand the bad areas and use a high-build 2 part primer on them. You can put it on with a brush a mop or anyway you want to, just get the repair "full" of primer. This sands very easily, maybe use 120 then 180 then 220 with a random orbital sander. On the compound areas, like the corners, only sand by hand with a sponge backer. Then paint
the areas or better yet sand the whole camper and paint
with a two part polyurethane paint
. Some just roll and have a helper tip with a good fine brush. If you can, spray it for best results. Good luck.