Taking it a step at a time

After the initial cleaning and assessment of your project, you should tackle your job a step at a time. Its easy to get excited and want to polish the aluminum right away. This will make you feel better about the purchase you just made..right?
Nonsense.
 Start with sealing the seams, around windows and vents too. Get the trailer dry inside and keep it that way.
Then move onto floor repairs. Th entry step area inside the door is prone to rot and rusted framing.
 If there are panels needing replacement in the flooring, now is the time to cut them out. Check the frame under the plywood for the rust that can be re-mediated. A wire wheel brush on the drill is a good way to remove surface rusting. Then a good coating of rust proofing paint like POR-15 or the less nasty and easier to apply Rustoleum will work. Coat it well with a brush or several layers of spray paint.

Scab in the new plywood, and coat the wood flooring with sealer, polyurethane or other similar stuff.

Make sure it is all level and you can move on to your decorative flooring. I prefer laminate or vinyl laminates. Stick down square tiles do not work well in the temperature changes, and will need replacement sooner than later. A good click and lock or glued edge flooring will work better. Be sure to leave 1/4 inch or so around the edges for expansion.

Carpet is ok to use, with an appropriate pad. Carpet is very forgiving to put down, but does not handle water well, and the vinyl planking will repel water which makes life on the road much easier. I am truly not a fan of carpet for trailers.

 This was the inside of my 66 on purchase day.

Old Asbestos floor tiles, stencils painted everywhere, dead rodents and such inside cabinets.

 After removing the rusted out Dometic refrigerator,this was the scene we found. The aluminum and wood pieces cover  a hole rotted underneath. Leaking from the unsealed roof vent for the refrigerator. Sealed the vent, and eventually replaced it. As for the rot and rust- I removed all the rust with a wire wheel and naval jelly. Then fiberglass and JB Weld was used to strengthen the outriggers. I would have welded new metal in, but this was not in my skill set at the time. I had a steel plate welded by a a fab shop under the entry area to support it. This is another problem spot for leaks, just inside the door. With the constant going in and out it is an area that needs attention. But common sense and visits to the hardware store can solve the issue.  Local fabrication shops and welders are good to know.
The Dometic was rusted out and originally we replaced it with a small all electric unit. This served as a temporary fix, because in the design of our Airstream, the fridge is built under and supports the entire kitchen wall unit on one side. So the correct size is necessary, and also impossible to find.

I saw a buyer of a 1967 Airstream mention remodeling and gutting theirs on a forum post. I contacted them and then purchased their original Dometic unit which worked.

After locating and installing the original refrigerator (  a 1967 model), it was installed over the repaired outriggers and floor. New cork look edge locking tile was installed.