Hi All,  I have a 1929 Mason RA that I am restoring.  It also has
inserts glued on top of the metal secondary valve ports (sort of like
heavy bellows cloth that has been varnished).  The hole size in these
inserts is about 0.210", thus reducing the effective hole size of the
metal plate underneath.

Certainly if Ampico did this to their top-of-the-line pianos there must
be a good reason for it.  Can anyone confirm whether or not I should
replace these "hole restrictors" with similar devices when I rebuild
the secondary valves?  Does anyone know of other Mason pianos with the
same thing?

Thanks,
Pat DeWitt