Rental trucks, U-Haul included, have their balls welded on, and they are mostly 2", and that size Airstream usually takes a larger ball that that.
If you get someone else to tow it for you, I suggest that you insure the trailer, comprehensive. Liability is covered by the tow vehicle's insurance. Trailer insurance is cheap, compared to motor home, or car insurance. Be awful if it got stolen, or damaged on the way.
Like it was said, get on the Airstream, including Vintage, and other aluminum forums, (Silver Streak, Avion, Streamliner). You will meet another batch of dedicated folks.
I have an Airstream, ( also had a 53 Silver Streak Clipper), a Fiberglass RV, and a Tiny Trailer, so I keep my eye on all three groups.

RVing, and fixing them since 1968.
Never drink and drive, ever.