We were at USF/IOA last November and I searched high and low for these straps.I finally found them at the IOA in Toon Lagoon.Right in front of Dudley Do-Right was a cart,selling water and snack food-they had them!In all my searching,I never found them at US,although a friend of mine what in the spring and found them at a snack cart in front of BTTF.Good luck in your search.
Does anyone know anywhere else to get them?I'd be interested in hearing,so I can plan for our up coming trip in December.