Hey Squealers, thanks for the compliment! Ya, UP Builder restored a Holiday of about the same size.
Just looking at the pictures and from your description, I believe you will have a bit more work than originally estimated. The usual schedule of events is: The roof leaked at joints or through holes. The previous owner didn't see water problems or just let them go. The wood framing and floors failed due to rot and continuing intrusion. Owner sells trailer for close to nothing because of the amount of work needed vs price of same model in good condition.
There are two methods to proceed with repair: remove the exterior siding or remove the interior paneling and everything in the way. If you remove the siding, you'll probably also have to replace some paneling. When you have the frame exposed, you'll probably want to upgrade or add wiring runs and insulation. The insulation upgrade is the best modification you can do, it keeps the interior cooler in summer and saves heating costs when cooler. It also makes the interior a lot more cozy and quiet.
I would also look at replacing antiquated appliances with ones that use less energy or have better functionality. The stove burners can be soaked in a sauce of baking soda and water to remove grime. The water heater is best replaced with a new tank model. The on-demand heaters don't work out that well for trailer application, there is not enough demand to keep a constant temp for showering. Look on Ebay, Craigslist, or at an RV salvage yard for cheaper replacement.
The best advice I can give anybody restoring one of these vintage trailers is: Make a plan/s. Take pad and pencil, list what's needed, and draw things out. There are multiple systems and locations in a travel trailer with limited space. The plans will help to insure that installations are done in appropriate schedule and your new work isn't removed to accommodate a necessary item in a location.
Good luck with the restoration, if you have questions, fire away.
