I've been restoring music machines for many years. Real "restorations", not "reztorashunz" as done by those who butcher rare machines. Currently I'm restoring a 1925 Wurltizer band organ, a particularly detailed job since only 40 of this model were ever built. I've seen and tried all kinds of materials and associate with other serious rebuilders who have done the same and I can tell you that the best thing to do is DON'T get cleaver. The factory used what they used because it worked, was correct, and was reliable for many decades. Modern materials, with few exceptions, are almost always the wrong thing. We've all seen what happens when "rebildurz" do that sort of thing on pianos. A very effective design that many companies used was thin pneumatic cloth backed with packing leather, soft suede both sides. Both materials stretch too much on there own but used together they make an excellent, strong, and very air tight valve. Use the Australian cloth from Schaff. There are a few different suppliers for leather and quality varies from time to time. Currently I recommend Organ Supply Industries http://www.organsupply.com/ You will be required to buy a full skin but it isn't that expensive and has many uses in player work, particularly for gaskets. Use PVC-E and glue the pneumatic cloth and leather together. It has to be a very tight bond or it will leak. Place it between two pieces of thick hardwood and use every clamp you can find in your shop to squeeze the hell out of them absolutely tight together. If you have a vacuum veneer press that is an excellent alternative. When it is dry it will have the perfect stiffness, will seat very nicely, and last for many many years. Install with the rubber side toward the valve holes. Rob Goodale, RPT Las Vegas, NV
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