Yeah, he did build them (and that one is a nice one too- sandwich construction. Wonder how much that sold for- the singles usually sell for more because there's less of them!) but only because customers insisted on the single. Bob was a cranky bastard according to Elwell, and was convinced the twin set up out toward the rail was the only way to go. He built a pointy nosed, sub 8' twin in the early 50's too. This is not an attack on single fins or old school boards from me mind, I quite like a more contemporary single, but on the mini Sim platform is just not the best idea, I think you're hampering the good points of the design more than helping. They work great as a twin, fun and fast little skateboards on a wave, so why mess with that?
surf nonsense: http://waveslide.blogspot.com