I replaced the floor last year. The tailgate leaked and could have never sealed from new. the tailgate hit at the bottom leaving a huge gap at the top. I fixed that and posted pictures of the whole project.
I took the trailer down to get an estimate this morning they are supposed to email me a quote. I would post pictures of the damage but I can't figure out how to do that.
I am considering fixing the spots that are affected and then covering the exterior with smooth aluminum. I machine aluminum for a living and I got a quote today it would cost me about $1200 in pre painted polar white aluminum like they use on car trailers. I think it would look pretty cool and it is a toy hauler so the look would work. My plan would be to fix all the damage then cover it with aluminum. I saw a trailer done this way at the coast this last weekend and I thought it looked good.