We had a 1989 34V Avion. These are very well built trailers and are superior to the Air Streams of the same vintage.
A couple of areas of concern are roof seams. Remove loose sealant and cover with the silver Eternabond tape. The front rock guard will become brittle and crack. Replacement fiber glass is available but not cheap and hard to mount. many remove the guard and take a chance with the curve front windows. If you break one of these...good luck. The hinge attachment for the rock guard can leak and the floor below may be rotted. Also to the right of the door at the porch light, these are prone to leaking.
So check the floor edge to be sure it is solid. Another place is the sealant at the tub drain can harden and leak onto the ply wood deck and root it under the tub.
Check the condition of the under belly and look for corroded metal around the rivets. You will need to repair before you start loosing sheets on the bottom.
Other than these few issues, if the trailer has been properly maintained, it is a matter of redecorating and maintenance.
That vintage Avion had anodized finish and were not meant to be polished. There is a commercial product called EverBrite that rejuvenates anodized aluminum.
Amateur Radio Operator (KE5DFR)|Full-Time! - 2012 6.7L Ford Crew Cab Dually -2013 HitchHiker Champagne 38RLRSB - Travel with one Standard Schnauzer and one small Timneh African Gray Parrot