With a 50 yr.old Airstream, you're in for a series of suprises. Start with basics.
New tires.You seem to have had the running gear checked out.
I would do the easy stuff, like replace all the old electrical outlets, that probably hardly hold a plug.
Thats gives you a look at wiring inside outlets, and makes sure every connection is tight.Also, replace the junky 12volt lighting with bright low draw LED lights.
Maybe put on a new 30 Amp power cord, save future problems.
All electrical parts don't age well, like a fine wine.
If the old refrigerator works, it probably won't for long,+ is terribly inefficient.Junk it
Look at water heater, and replace, depending on age.Same with plumbing fixtures, that stuff wasn't great when it was brand new.
Just things like that, and that gives you a little deeper look at general mechanical condition.
Things like replacing all old battery cables, you keep eliminating future failures.
Don't try and work around old junky parts, R+R as much as possible.