G'day Callie,
Stylophone? Plastic Wobble Boards yet?!?
Back then they were made of 1/8" Masonite - the same stuff Rolf used to paint on (cheaper than canvas) ... Apparently he invented the wobble board while waving a masonite-based painting in front of a radiator, in the cold of London's Earls Court, trying to dry it quicker.
Regards,
Bob Bolton