Hello,  After reading various discussions regarding the seal in the
Ampico A take-up spool, I'm surprised that no one has mentioned
checking for a clogged or partially clogged bleed in the shut-off
valve.

While a good seal is necessary at the take-up spool bearing, its
airtightness does not have to be absolute.  Before blaming shut-off
problems unconditionally on seal leakage, it's a good idea to make sure
that the bleed in the shut-off valve is not clogged.  This bleed, if
clogged, will cause the piano to shut itself off even with the most
minute amount of leakage.

The shut-off valve activates whenever there is enough airflow to
overcome the bleed.  If the bleed is badly clogged, even tiny amounts
of leakage in the region of the opening covered by music roll paper may
activate the valve.

The shut-off valve tends to pull in all kinds of foreign matter over
long periods of operation, so check it carefully.  It's best to take it
apart for cleaning and inspection and check it out thoroughly.

Dave Saul