In the 081022 MMD Dave Geissinger mentions the Wurlitzer unit-block parts
that are available from Player Piano Company.  If this is in response to
the recent thread started by Julie Porter in the 081019 MMD, one must be
aware that Wurlitzer's 4-in-1 valve is quite a different animal from its
unit block.

The unit block concept, invented by Charles V. Jameson (U.S. patent
1219104,issued March 1917), is the one adopted early on by Wurlitzer in
their "Jameson chest" design, which replaced their original valve chest
having integral internal valves.  In organs using the unit block concept,
a bad valve can be replaced simply by removing the unit block and
screwing another in its place, making it unnecessary to remove the whole
valve chest to dig out the offending valve.

The 4-in-1 valve, a later development which I imagine Wurlitzer
introduced as a cost-saving design, uses a cast pot-metal valve unit,
each unit containing four valves instead of the one.  They share the
weakness of all pot-metal products, their housing cracking and crumbling
with age.  Player Piano Company does not offer any replacement for that
kind of valve, nor does anyone else that I know if.

Matthew Caulfield
Irondequoit, NY