The Airstream trailers are known for a very weak frame. They have what they call a semi monocoque structure which uses the shell as part of the structural integrity of the frame. The problem is the wood floor is sandwiched in between the shell and the frame and when the wood floor rots, the structures separate.
You may want to consider buying a used Avion which has the best of both worlds, an excellent shell and a strong frame. You won't have to pull the shell off most Avions for a rebuild because the frame is failing. Those old Avions have one of the best frames you can find on a TT. Get one that spent most if it's time in a dry climate and you will probably have a gem. You should be able to get a good condition 1980s Avion for less than $10,000. For that price you can afford to put in a new interior with new appliances.