This boat is sailing across my screen. Don't know if it still exists in 2014.
My dad video taped his old family movies and made a dvd. The shark was sailing in the video and this is a screen shot. He is sailing with 1 of my brothers and 1 of my sisters and my mom was filming from our dock around 1965. The boat was really US sixty something but the old owner had kept the sail number and given the 268 number to the used boat when he got his new boat around 1965.
As for old Tornados; i crewed on US9 in 1968 as a little grommet. Those old boats were minimum weight. Around 350lbs or whatever. They were Sailcraft of England made. Within a few years there were at least 3 builders in England exporting boats to the US. We had US 40 and it was an original Sailcraft plywood model. Those boats had Seahorse sails as original equipment. To downhaul the main we would sheet in, stand on the boom and crank down a thumb screw on the gooseneck to hold the downhaul pressure.

My father & I use to sail a 1977 Chesire Cat (14' version of the Isotope). Unfortunately, didn't bring it with me when we moved out west.