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.