What is 'jeweler's steel media,' and where would you get it? Looks useful.
Also, be advised that the guys who restore player pianos (visit them at the Mechanical Music Digest, free and fun to read) use a host of different materials to make their pneumatic 'pouches,' as they're called. There are hundreds in some instruments, acting as pneumatic-to-mechanical transducers, pneumatic amplifiers (really), pumps, motors, and mechanical-to-pneumatic sensors or transducers. They all look like cuckoo bellows, and there's always debate over which material to use.
There's rubberized nylon, rubberized canvas, the thinnest leather imaginable, rubberized or non-rubberized nylon cloth, zephyr skin (I have no idea), and your Tyvek. I have missed others. There's an equal level of debate over which cement will hold these onto the wood substrate. Elmer's, hide glue, PVA-C (I have no idea), and I think rubber cement may be leading contenders.