Sorry for the delayed response. I had an e-mail exchange with Richard Lawson of RL Music (rlmusic.co.uk) a couple of months ago about the possibility of making replacement membranes for the Chroma. He wrote, "The Membrane manufacturing is going to be too expensive it seems after discussing this with my tech. The design of the micro-switches into the membrane itself means this is a complex manufacturing process that would require specialist tooling. Having some experience with restoration work, I know without even a detailed investigation that this is not going to be cost effective unless we were to sell hundreds of them and I doubt that is ever going to happen." I'm not sure how similar the Polaris membrane mechanism is to the original Chroma.

Chris

http://www.rhodeschroma.com/