[ Ref. 091209 MMD, Seek Cloth Punchings for Simplex Player Action ]

Personally, I favor using a slightly thicker valve leather in place
of the pouch leather inner valve facings, gluing the smooth side
directly all the way to the center hole and omitting the pneumatic
cloth punchings altogether.  This can actually improve performance to
the extent that the original pouch leather may stretch and pull away
ever-so-slightly from the rubberized cloth punchings to which it is not
supposed to be glued.

The thickness of the new inner valve facings should be such as to
permit use of the same or slightly softer leather to replace the outer
pouch leather facings, gluing both inner and outer with smooth side
against the wood, suede side out (just the opposite of the way Simplex
did it on ones I have seen).

Leather must be non-corrosive and selected to permit a valve travel
of .032".  Fine tuning of travel is done by as-little-as-possible
peripheral bending of the upper valve seat.  Don't seal until travel
is set! To decrease travel, press inward at center; to increase, remove
valve and re-insert the plate upside-down for adjustment by
trial-and-error.

To obtain the essential flat valve surface I would make a jig using two
square pieces of a Plexiglas-type material, 2" X 2" by 3/8"or thicker,
one piece drilled to accommodate four valve stems; these holes being
cleanly made and no bigger than necessary to allow easy insertion and
removal.  If glue oozes out around the stem, you are using too much!

Pressure applied by weight need be only a pound or two.  The 3-legged
guides are put in place after glue is dried and secured with shellac.

With a fast-setting glue such as hot hide glue in winter, the
inner and outer facings are best attached in two separate operations.
To speed up rebuilding the valves, you could make a couple of jigs,
preparing the next group while glue is drying on the previous.

I would imagine your nickelodeon, if original circa 1920's production,
would be a Nelson-Wiggen, that company having made extensive use of
Simplex stacks.

Jeffrey R. Wood