That would be Horton Brothers, I believe. And Germany had flying wings up and flying before the end of the war, that’s how brilliant they are when it comes to aviation! ... er, unless you’re being tongue in cheek ... if so, the name “Horter” goes over my head (no pun intended!). But I think you may seriously be on to something, in a way. I’ve often thought that IF some of these weird sightings are terrestrial in origin, there’s about a 99.99 percent chance some Germans are behind them! {^) BMW started out as an airplane company and its logo was inspired by a propeller — they take aviation more seriously even than they take their cars!
And while it was initially tongue-in-cheek, the more I thought about the location, the more I thought that it was a definite possibility.
There is a lot that isn't said about the Horton Brothers' work during and after the war.