Hi All,  In a personal letter, Robbie Rhodes asked, "How can one
distinguish between the Standard, the Amphion and the Pratt-Reed
player actions?"

The Standard action uses a four hole (or double-hole) tracker
service and the bellows on the tracker device are horizontally
oriented.  It also has an "S" monogram on the pump pedal mats.

Amphion made two types of actions.  Prior to 1913 the two wooden
sections of the three valve chests were glued together with a card-
board divider, which included the valve seat as a clinched grommet,
dividing the upper and lower chamber containing the rubber cloth
pouches.  The later type had the 'clamp-on' unit valves; first the
upside-down type, which is most common, and later with the valve facing
up.  Amphion is also recognizable because the exhauster bellows are
mounted on the front of the wind trunk which open at the top.

The most positive identification of the Pratt-Reed action is probably
the valve, which looks something like a very small wooden yo-yo with a
hole on the side with the leather and a wooden tip protruding outward
on the side without any leather.  To examine the valve, remove the
cover plate on the atmosphere side of the valve.

The Pratt-Reed actions were of the two tier type.  The early models
used a primary valve.  In either case, the secondary valves were
oriented horizontally.  The style A had pneumatics that face forward
with linkage to lever underneath the player stack.  The primary valve
was to the rear, under the row of pneumatics.  The style B had a double
row of primary valves on top of the action.  But it took more of a form
of the models to follow in the single valve type, with the valve over
the pneumatic.

The later single valve actions had a dowel through a guide rail
connected by wire linkage to the pneumatic finger, and another style
(32) had the front of the pneumatics slightly elevated and with an
extended finger on the bottom, to meet directly with a regulating
button on the abstract of the piano action.

Another popular action is the Simplex.  The Simplex uses a patented
tracker bar with 'trapezoid' looking holes.  It also has detachable
unit block valve/pneumatic units and the three tier stack was designed
to be 'universal' in adapting to various piano scales.

The vast majority of the information above came directly from the
Player Piano Co. parts and pubs catalog (1983-1985).  To find out
how to get a free catalog, visit my PPCo web page at:

    http://www.player-care.com/catalog.html

Hope this helps,

John A. Tuttle