Spotted this today and had to stop and snap a pic. I believe it's an actual 1966 Airstream but I didn't ask if the bike in the back was a Harley. Regardless, it's just not something I see very often. The 292 powered Chevy is definitely pulling quite a load.
The owner happened to be present and I immediately noticed his European accent. Turns out he's from Germany but spends 5 or 6 months each year in the US. He purchased the truck in South Dakota and stores it near or with a relative in Nevada. He and his companion are returning from a trip to Sturgis. Maybe that's why I assumed it was a Harley.
Their next destination is Arkansas so I mentioned the various parts vendors in Kansas City and encouraged him to check out the Stovebolt website. He was very appreciative and gifted me an expired German license plate he had in his storage box. But, not before he showed me some pictures of his '59 Apache he has back home in Germany.

John