Greetings and welcome to the vintage Airstream hobby. What made a nice trailer in 1966
isn't what makes a good trailer in 2020. As others have said, you bought the trailer with a purpose in mind. And maybe you have inspected it thoroughly now that you have access to it. Maybe the trailer has some special province like owned by a famous movie star, or Wally Byam's personal caravan trailer. Restorations are much more involved than renovations.
I bought a 66 Trade Wind. I loved the size and the vintage design and construction of the thing. But the thing really didn't function well. The waste water tanks were woefully inadequate. The axles were shot, subfloor was rotted in the rear, appliances didn't work, the plumbing didn't work, some of the woodwork was warped, the mattresses were shot, and on and on.
So off to work I went. I believe I renovated the thing into a comfortable modern travel trailer that looked like a 66 Trade Wind. I believe you can recover most of your costs if you do the work yourself. Vintage Airstreams are popular with folks who don't want to take the time renovate them.
Here are some photos of my finished renovations. And here is a link to a beautifully renovated 68 Trade Wind. The 67 and 68 had several model year changes over the 66. Take a look at this classified ad.
Most important, is you enjoy your ownership experience.