Greetings,  during the recent restoration of my 1912 Wurlitzer "B"
I realized that it had been "refurbished" probably sometime in the
1920's.  The original roll rewind mechanism had been replaced with
a unit that had the 4-valve die-cast unit attached.  The die-cast
parts were history -- distorted and not restorable.

There were several options on how to restore the rewind mechanism for
the instrument.  The patents available on MMD provide an excellent
reference on how it all worked.  But there was the challenge there to
replace the instrument's mechanism as it had been modified later in
it's life.

It seems like the 4-valve unit was an afterthought to be used on the
rewind mechanism.  One of the valves wasn't used at all and the use of
the other three for 'lock and cancel' logic was by either dumb luck or
trial and error; it is weird, but it does work!  A careful study of the
patent proved why.

At any rate, I duplicated the die castings by milling a copy from
a block of ABS plastic resin.  I have the drawings of the valve on an
ACAD format (they are cryptic -- just enough to produce a copy for me)
but I will be happy to share what I have with others truly interested
in the subject.  There are translation programs available to convert the
ACAD format, but they may lose the inherent dimensional information.
I also have photos of the reproduced valve mechanism.

I'm not sure what it would take to polish this info up to post on MMD,
but I'm sure it will be of interest to someone.  My valve block works
great!  I think anyone that has precision woodworking skills could make
a good copy.

Larry Emmons