Looking at a new (used) 5th wheel today!
 

We love the features of our current Avion, the build quality, but it comes with a hefty price: 10,000 pounds. It puts the truck right at limits, making it more like work than play.
That, coupled with limits on trailer length in several National Park campgrounds, has sent us on a search. 27' or under was the target.
This link is a similar style trailer, same vintage but 29' long and heavier.
1993 Alpenlite 29' 5th wheel trailer w slideout
Note that I lose my radiused corners along the top. It is as sharp a corner as it gets. :(
That's the bad news.
Now for the good news. That goofy luggage rack on top is a complete liability, causing leaks, and nobody ever uses them.
I am going to use it as the aft attachment points for a turtleback, leading back to a removable tail. It will have a pair of opening doors to let the AC unit breathe, and I will store the tail pieces up there when going into those tighter parks. I can't simply fold the tail, it would block the view out of that huge kitchen window.
I'm thinking 2 pieces each side, trapezoids that will taper in plan. two pieces on top, same thing. two radius sections to bring it together.
The turtleback will be smooth and rounded. I just need to get some sketches together.
Any roof vents forward of the turtleback will get a template-styled failing.

gently worn 5-wheeler
 

Well that'll keep you out of mischief for awhile!:p

Sounds like a good project for you to do and me to follow. I'm in.

Not to make this into a blog post, but so far 675 miles driven @ 22.8 MPG, looking at trailers that were either mildly or grossly misrepresented :(

Yup, that's always been my headache with RV shopping, they never leak, yet there's always water damage visible... and the lights never seem to work :)

I would be quite concerned on a trailer of that age and build quality of roof deterioration and the extent of wall delamination. Not if, but of how much. The DIY stuff on WOODALLS would make me leery of ever attempting this (not the skill, but the extent. And one still has a wood-frame in the end).

No wood frames, no lamination to delam. All aluminum framework like my Avion. The big concern to look for is electrolysis, just like the Airstreams.
The pre-92 Alpenlite has a single sheet of aluminum for the roof over the back 2/3rds, and the front 1/3rd is part of the fiberglass front cap.
The concern there is the sealing. clean up the old caulking and re-apply the expensive self-leveling sealant.

Good to hear!!