When did the Hardman Duo's have traditional valves and then
plastic valves?

The 1956-59 Hardman Duo console player was built with a traditional
single valve action above the keyboard and two-tier stacks, very
similar to 1920s Hardman Playotone single valve player pianos.

The air motor is on the right hand side of the spool box, and the
automatic tracking unit is located on the left. A non-transposing
tracker bar with Standard Player Action tracking ports was used in
these. Also, the play/reroll lever is also found in the keyslip.

The re-designed Hardman Duo's and 64-note Pianola spinet models
apparently made their appearance in 1960. The entire player stack was
relocated below the key bed and the plastic unit valves were substituted
for the wood and metal valves of the earlier versions. The Play/Reroll
lever was moved to the spool box then, too. Some 1960 88-note console
players are labeled "Hardman Duo", "Cable", as well as "Ivers and Pond"
but all are identical instruments.

The 1950s Duo players were mostly foot impelled only, but I have
seen some that contain Lee "Silent Suction" units placed in them.
There are no automatic reroll pneumatics installed in them, though.

I'm not sure when Aeolian started making the 1960s Duo models foot
pedal or electric, but the 64-note spinet models were foot impelled
only in the first few years of manufacture. Towards the mid 1960s
most "Pianola" spinets were foot pedal and electric operated, then
auto reroll and shutoff was soon to follow.

David Oppenheim
Savannah, Georgia 

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 [ -- Robbie