I noticed in the front left pass through storage area that it was wet after a strong rain. I started poking around and the corner (less than 2" square) is soft. The piece of wood that runs across th...
Not sure why you want to remove the belly fabric. I had a soft spot the same size and location as yours. I carefully pulled back the carpet in the storgage pass through, removed all soft wood, coated the adjoining area with "git rot". Then mixed fine sawdust with git rot to make a paste and filled the hole. Glued the carpet back down when dry. Very solid. For the cross member if soft, drill some small holes for better penatration and throw a coat on it too.