Hi. I need a shower "curtain?" replacement for my '79
Sovereign. the original is made of a flexible plastic that actually folds up, sorta, as you open and close the shower. It works like any folding door, but is made of plastic. Does anyone know where I could find a replacement? The one I have has gotten old and brittle and is badly split. I could just replace it with an ordinary shower curtain, but would prefer something like the original if it is available and affordable.