I watched the video. Impressive stuff...
There is more involved than asked. The plastic tube has to be continuous and/or have welded seam. Additionally, how do you plan to slip it on the ring since it has no open ends ? Moreover, if this is for the same performance, I am sure it will have to have specific material specifications so the ring "feels" and reacts the same as the old ones.
Armoflex is definitely not the type of material you want to use. I don't think Plumber's trade will be able to offer to you material as delicate as your project requires. As somebody else mentioned here before, best way would be to go the prop manufacturer.