I am seeking advice on regulating the treble and bass soft control
governors on an Otto Higel Metalnola player piano.  On examination
of the units the leather pouches and all internal parts appear to
be in good order.  The "Soft Bass" and "Soft Treble" buttons do not
make any difference in volume and even if I push the governor bellows
closed by hand no difference occurs.

I realise that is a minor sort of expression unit and I would like
to correspond with someone who understands the system.  I have been
working in a professional capacity on player pianos for over 70 years
but I need a bit of help with this one.

Regards,
Albert Fox - Darnum Musical Village
Darnum, Victoria, Australia