Welcome to the forums.....
As you have probably deduced by now there're two types of vintage Airstream trailers for sale, trailers that are unmolested and gutted trailers. The gutted trailer ad allways states "Trailer stripped and waiting for your dream interior, all the hard work done"
. These trailer are easy to strip but a lot of work to reassemble.
Tips to hopefully make you succeed with your project.
1) Buy the trailer and take to a landscaping place or dump with a vehicle scale. Weigh trailer.
2) Very carefully strip trailer keeping a note book to note all electrical connections and measurements. Bag and label everything, taking lots of pictures. KEEP EVERTHING including anything you will throw away or eventually sell.
3) Back to the scale to weigh the trailer empty. This will tell you how much what you took out weighed.
4) Get your design together but understand this....Airstream built things lightly for a reason. If you want to replace that old plastic bathroom sink (which you will weigh seperately) with a glass one, go ahead, but you will have to take that difference in weight from somewhere else.
5) It's so easy to overload a vintage Airstream. Also be aware of the percentage of weight you add to the area forward of the center point and the area behind the center point of the trailer. Too much weight on the front will affect towing as will too much weight behind.
6) You may find that the layout is just fine but you wish to replace cabinetry. I built my cabinetry starting with a face frame, to which I added gables going all the way to the floor, but only going back from the faceframe just long enough to mount my drawer slides. No backs or even bottoms to save weight. You have to be creative and it can make things difficult to build.
7) I also revinyled my interior gables as they were very durable but lightly constructed with paper sandwich board between sheets of aluminum. It would be almost impossible to build gables as strong or as light from any other material.
Projects can change and you can find yourself looking at how something was built by Airstream and decide with a bit of freshening up it would work better than what you could replace it with.
For this reason.....keep everything!