While looking at folding wing biplane designs I stumbled across the story of Albin Longren. He was apparently quite influential and a clever amateur designer who impressed a a lot of people and even the navy with his designs. He was once vice president of Cessna yet nobody ever heard of him. He is credited with producing the first true monocoque fuselage using concrete forms and some kind of "vulcanized fabric/ wood veneer" method.
The Birdman of Topeka
The Birdman of Topeka