Another reason to keep the tongue flat or lower: Only the front
axle has
brakes. If the tongue is up too much, the braking
axle will have less
weight and could skid? Not sure, but seems it could.
A couple of us have done the gut, or nearly gut, of the trailer. Lot's of work. I'll be posting pictures of my journey in a couple days.
It looks like you are dealing with someone having done the same rooftop a/c mod as mine had: A 4'x4' sheet of plywood screwed into the ridges above the back vent, with an A/C mounted on top. A couple problems: You can't seal at the vent hole, and it's just bad where the a/c mounts. Very flexible and prone to leak. My advise is no roof top a/c on
Fiberstream, but that's not very acceptable to some. When this extra weight is put on the roof, it causes the walls to try to bend outward. As the screws holding the shell into the back of the
fridge and the kitchen walls and cabinets have been weakened from moisture/age/rot, the structure can't take the weight. The kitchen wall and
fridge wall need to pass the roof load to the floor, but there's no steel in the floor where it needs to be. This leads to bowing of the floor with moisture. It's a domino's effect. One thing that may lead to the impression of the walls bowing is the shape of the trailer. In order to get it out of the mold, they designed the top of the trailer walls tipped in from the bottom. The bottom of the trailer is wider than the top. Don't try to make the outside walls level. It's impossible.
Wow! Too much venting from experience. We are loving our rebuilt trailer, and just used it this weekend. I wish you well!
RI