Interestingly, around 1968 or so?, we had a careers convention at school - and one of the companies present was ICL (the computer company). One of the things they gave out was a 'hexaflexaflexagon' (as they called it) - I still had mine not so many years ago, and had obviously long since sorted out the sequence of working it. As it was a promotional item it had ICL information on each side, and the 'game' was to go through all the correct full sides in the correct order (the correct 'colours' weren't good enough, the pictures on each side had to be correctly aligned as well).