This discussion has led me to wonder why rubberized cloth was used in
the first place in player pianos.  Does it stand up better than leather
to the frequent repeated openings and closings of piano pneumatics?
Or was it just cheaper?

Nice quality thin leather seems pretty widely available now (albeit
at a price).  Is anyone using it for routine piano work?  As John Page
noted, it seems to work quite well in organ pneumatics.

Roger Wiegand
Wayland, Massachusetts, USA
http://www.carouselorgan.com/