Fiberglass was the wonder material back then. Wild that they had to sculpt these full scale out of clay... just like cars, and then create molds yada yada. Also interesting that these were so perfect in 1955 and the character costumes so dreadful. Plastics were in their infancy and composites were near nonexistent. Love the Smithsonian... even though one can only handle it in drips. Just too much stuff.