Hello Jean -- Welcome to the Forums! Whether restored to original condition or redesigned, you will find that it will cost the larger part of buying a new Airstream. The difference is that you may end up with a vintage article of great enjoyment for years to come. That should be your motivation. It is not likely that you would profit from a restoration and resale.
I would recommend listening to episodes of
Welcome to the Frontpage - The Vintage Airstream Podcast. One of their contributors, Colin Hyde of GSM Vehicles in northern NY (Plattsburgh), builds new frames and more. Do your homework whatever you choose! You might find you'd rather have a different year, length .... many variables, likes & dislikes.
You should plan on posting some photos if this unit was vandalized. That will help you get more accurate input about whether this is worth pursuing.