The Excalibur was the brainchild of Brooks Stevens and was part of a "classic" revival of cars in the 1960s. Styling was modeled on the early 1930s Mercedes SSK. Underpinning was Chevy. There were a few iterations but the best was the earliest pictured here. These were factory built and tested cars, not some kit car. The video link below is a scene from "In Like Flint" where secret agent Derek Flint played by James Colburn pulls up to his private jet in an Excalibur. The music, setting and Colburn's wardrobe scream the 1960s.