My Fiber Stream
also suffers from bulging wall surfaces even though I never had a roof A/C unit. I speculate that 30 years of dryrot within the partition framing in addition of rusted screw fasteners along with bouncing down the road
on shock-less leaf springs have contributed to the present condition. I think that attaching the interior partitions were used to correct a less-than-ideal shell profile rather than the shell profile dictating the shape of the interior partitions. I fear that there is a lot more flexing happening than I am aware of...
My ideal would be a total frame-off restoration, where I disassemble all of the individual components completely. Have a new frame built, and rebuild the whole trailer. There is a gentleman in Canada who has been doing this with a 17' Boler
who is framing his internal partitions and furniture in aluminum square tubing.
I would copy that and use fiberglass panels instead of plywood for interior wall surfaces. I also dream of replicating the Escape's
insulation & vinyl surface.
I have neither the time nor the money to attempt this.
Instead, I accept the trailer as it is, and go camping.