Super8 was launched in 1965 by Kodak, and the Fuji Single8 in 1966. Most camera manufacturers went with the Kodak system with at least 39 different Super 8 cameras available by 1966, compared to only 3 Single8. Two of these were Fuji products, and the third was the Elmo C200. It is described in my book (written by John Wade) as having interchangeable backs, a bit like some medium format cameras. Perhaps the Elmo company were unsure in the early stages which format would prove more popular. Their product allowed the use of both. It was followed by the Elmo Multi-Guage camera which took single, super and double 8 films. The book is called "The Collector's Guide to Cine Cameras" published by Hove Books. It has a nice picture of a C200. Nice find! Alex