I have a similarly built northern lite camper that delaminated and bulged the fiberglass shell after winter use. It occured where the cabover attaches to the main body. I repaired and reinforced before it got cracked and more difficult to repair.
Basically laminated the inside wall with prefinished oak flooring, 3/4" and thru bolted an aluminum plate to the outside. Thereby squeazing the bulge and wall back together. This plate acts also as a strut across the area of required compressive strength and keeps it from bulging from the pressure from the weight.
May be off topic a bit but gives an idea of some other ways to deal with this issue.