The wood is usually pretty soft there and there is little damage on older hulls. Though eventually you should replace the carpeting when you get a chance. The bunks probably are not in bad shape, just the carpeting. Newer 20 trailers have the rear bunk bracket lowered about 3/8 to a 1/4″ for a drop and to prevent this from occurring as much, though the hull can slide back now when unconnected.