I'm currently restoring a 47. Hope you don't mind a few comments. These trailers are beautiful and worth restoring. However the market is thin, and restoration is expensive. Accordingly most restorations are difficult to justify financially.
While I'm not an Airstream historian or much of an expert I quickly realized that these old pipe frame units were constructed to be towable by vehicles underpowered and under braked by today's standards. That is, they were built very light, with minimal structure.
My pipe frame had folded at the leading edge of the trailer. A previous owner had bent it back and reinforced the pipe with angle iron. I've replaced the pipe from the Chassis forward with schedule 40 pipe, and reinforced the aft pipe with a steel plate spine. It has been a pretty time consuming job, but I wanted to keep the old trailer as original as possible.
If you aren't too concerned about orignality I'd recommend that you remove the shell and find a local trailer fabricator to build a new ladder frame with modern chassis. This will save a great deal of time, and likely a few dollars.
From what I could see of the trailer, the trailer shell looks pretty good, and includes most of the interiror.
By the way, if you do buy it and don't want the old stove, let me know. I need to find one.
Best of luck