Mark Haas inquired about the availability of the celluloid grids of
the Ampico "B" pump spill valve [180610 MMDigest].  I use Plexiglas
to make up new ones for the one in the pump and usually the one in
the pedal pressure regulator too.  You could use wood as well if
you like.

The thickness of the new material you use may be thicker than the
original celluloid but this is okay so long as the finished block is
the same height as the original; you can adjust it by shaving some of
the wood block down.

I use the old one as a pattern and then drill holes at either end of
the slots and finish it off with a file to make the slots.  It is not
a big deal to do it.

Good luck, Mark,
Ben Gottfried - Ben's Player Piano Service
Richfield Springs, New York
http://www.bensplayerservice.com/