Hello fellow MMDers -- I have a question for the group at large.  I am
a player technician and restorer with over forty years in the field.
I've handled many, many reproducing pianos over the years, dozens and
dozens of Duo-Arts of all types.

I have in the shop for repair and upgrade a 1926 Steinway AR in a
beautiful art case.  It's the "long scale A", typical late 'twenties
Duo-Art, very conventional.  It has previous restoration work, mostly
functional.

The Expression box has an internal crash valve, as expected, but
there is no exterior primary valve to actuate the crash.  Instead, it
has a bleed in the circuit and the pallet which is supposed to control
the crash (which comes on at power 15 or so) closes when actuated.
(A typical '20s box would have the pallet open at power 15.)

I have seen this type of box used in the lower end instruments, such
as Stroud or Aeolian, but never on a Steinway piano.  There is no
tube connecting to this pallet, leaving the 7/32" supply to the crash
permanently open (such that the crash is permanently closed, so no
crash function at all).  My question is, should I suspect that the
expression box is not original?

The balance of the previous restoration work is so-so (at best); the
springs for "Theme" and "Accompaniment" are reversed, with the stiffer
spring on the accompaniment side.

I am quite willing to change out the expression box for the more
conventional type which I expect to see in a Steinway, but I am
reluctant to do so if this is, in fact, the correct original box.  Has
anyone out there seen this type box installed in a Steinway grand?

Thanks in advance for your thoughts.
Tom Ahearn - "Player Piano Service"