The chassis is I believe is full gal on a KK, not gal dipped, so it would be fine, just ring KK with the model no serial no and theyshould be able to confirm this and give you assistance on what you should be looking for, it seems you will be seeing surface scuffing and scratches...sandblasting would be a waste.
But you have mentioned that the camper has done some hard work...so, put the emotions aside, check the camper out throughly and if you have some doubts...get a lower price or walk.