No info on the diaphragm, but there are a couple of places here in the USA that sell replacement odometer gears. I got one from odometergears.com years ago for a B3. Appears they may have one for the cable drive version in the urq: http://www.odometergears.com/cable.html Looks like they do global shipping, too. Eric R. '86 urq '92 urS '93 urS