Fixing saggy skin

Just me, but my 54 year old trailer has all kinds of "scars" that look like what your pics show, I just think of them as adding character and history to the camper. Perfection is not my goal, safety, comfort and reasonable historic accuracy are. No one is ever going to look as closely at the work you've done as you do. I'd just leave it as is and go adventuring. If you do, you will undoubtedly make your own dents and scratches which will only add to the history of the camper.

I agree with the above comments, I wouldn’t risk the paint job to fix minor waviness. With that said, I understand why it’s annoying after so much work to have skin issues. Hemet Valley RV told me they heat the building to 80+degrees before installing new skin.

It looks like you only have a few screws in the actual skin? The problem is mainly the lower skin? If yes, I’d consider waiting for a hot time of year, really hot, taking out the screws possible without damaging the paint. Glue tiny splints of wood (Like thin wood matches) in the holes without taking the skin off. Pull the staples/ screws off the automold at the bottom where the skin wraps under. In essence the skin would be loose/hanging. Park in the sunned wait for the camper to get really hot. Work from the highest loosened area with an assistant pressing gently down and add screws every 1 1/2’ or so working down. In the end you may have a 1/8” or so space to take up at the automold and the two or three screws originally there (removed and splinted) may need the holes pre-drilled to avoid shifting when the screws go back in. Hopefully that makes sense.

I’ve done this on one Shasta and it helped. BUT where it’s buckled at the S-lock/seam you’ll have to live with it in hot weather. I pre-painted the new screws beforehand. And you may or may not have to unscrew the jrail.

Our Shasta campers had very few screws in the walls. Our Forester had a screw every 3rd break (12”). Expand this photo and you’ll see I stretched it to about every 1 1/2’ apart.

All of this is based on the assumption the wall framing is straight.

The lower picture is when its cold. I added a few painted screws, but I think it just made it worse, it seems to make pressure points around them, I'm afraid that the aluminum will eventually crack. We live on the coast and I never even noticed an issue until we travel someplace hot. Unfortunately for me, I am anal and will need to try to make it better, even if it means that I have to repaint the entire side of the trailer. I guess I need to decide if I can live with more screws or if I want to tear it all apart hoping that it will be better when I am done. It's tough to get the skin warm enough, since it's cold here. Even in the shop with a heater, I am never going to be able to get it as hot as it gets when its 100 degrees out.