From what I know there were 4 versions The original was the I beam winged 69 sweeper. When Windy returned to the hobby He built the first foam winged version which is known as the 1980 sweeper that Bob Hunt cut the wing and tails for It is the one that has been re furbished by Bob Zambelli and is hanging at Brodaks . Then He built the sweeper 900 which was jet styled I believe this one was the largest and from what I herd it crashed due to wing failure. Then he built the final version which was the sweeper MIG which he went on to finish in the top five at the US Nats in 1983