Long story short:  Spartan Aircraft Company of Tulsa, OK, founded by an oil baron in 1928,  was sold a decade later to an even richer oil tycoon, J. Paul Getty (richest man in the world, “The meek shall inherit the earth, but not its mineral rights.”).  Spartan made really good planes including the oil magnate luxury special Spartan Executive that cruised at 200+ mph with 1000 mi. range.  At the end of the war, the company pivoted to expensive airplane-inspired aluminum monocoque mobile homes.  Spartan folded in 1962.