Along the right edge of the "Portal" page, the 3rd section down is "Airstream Inspectors."
You'll want someone who's done a big restoration, or at least *I* would if I were looking for that kind of project. I bought our first trailer in 2011, but I was looking for something close to ready-to-camp, so I had very different criteria.
Just above the drop-down for 'State' in the Airstream Inspector section is a link to the Inspector's Checklist
, a great resource. Much of it talks about stuff you won't care about if you're going to gut the interior.