My own 1930s Weissbrod upright has leather key bushings and I've encountered them on other German pianos of the period. David. "I now use calfskin strips for most key-bushing jobs. My supplier (Baumgärtel) has two thicknesses -- 0.9mm and 1.1mm, which is 35, 43 thou, and that is fine for many European pianos. American pianos must be very different. I personally would not waste my time using any material that has not proved itself to last at least 50 years, and leather bushed keys I know will last for 100 years of moderate use. JD"
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