I was asked to stop by and look at a project trailer. The Argosy is a 74, 28 footer.
It had already been gutted and that made it easy to see what it needs.
Which is pretty much everything,( though not totally)
I suggested the owners start at the bottom, meaning cutting out the bad floor sections, and checking for frame damage. Then replacing the needed plywood and sealing the whole floor with a waterproofing product.
Sealing the outside seams, and especially around all vents, windows and trim would be done too.
Then they can move up to the plumbing, and electrical.
The old Dometic fridge needs to be checked out and also the water tank. Hooking up to water supply will tell the tale on the pipes.
Then when all that is done, they can start the reconstruction of the cabinets and interior items as they choose. Using little or a lot of what was pulled out. Most of that seemed to be in OK shape.
Slow and steady....
The LAST thing will be painting the body shell. I suggested a trial camp out first. The shakedown will let them know what else needed to be done before the painting, which is a lot of time and expense.
Starting low and slow is the best route to go. Sealing and keeping out the weather is most important.
Ripping everything out, including walls, in my opinion is not a necessity.
Nor are new axles. If it rolls, tow it.
Check the bearings though.
Once you are sure that the trailer works for you then you can spend that extra money on whatever you want.