The Rocketeer Reviews
The reason I bring that up: because the makers of this film (from 1991) must've at least been aware of the existence of the same sharing, as it does, more than a few similarities. This is set in the late-30s (so pre-war), and tells the story of Cliff Secord, a pilot who finds a one-man jet-pack (later revealed to be invented by, and stolen from, Howard Hughes) hidden in his hanger. The gangsters who stole it, on the orders of Timothy Dalton's screen-star (and secret Nazi spy) Neville Sinclair are soon in pursuit, as are the FBI and Sinclair himself, leading to a show-down on board a German Zeppelin.
Unfortunately, the (pre-Jurassic Park) effects haven't aged all that well. That's a pity for a film that is, essentially, a comic-book movie from back before comic book movies were the 'in' thing! James Horner's musical score, on the other hand, is still pretty catching.