I guess I have to remove the aluminum skin.

So I was hoping I could keep the skin on the outside. Well, that didn't work out. The outside frame beams that are curved and run  front to back were rotted. The were not even attached to the floor anymore, the front and back halfs of the trailer were just loose and dangling. I could lighly jump in the trailer and the floor would bow and huges gaps would appear between the floor and front and rear halves allowing light to pour in. At least the rotted frame sections were curved and made of polar that had been bent with steam and heat.