Years back the Musical Museum in London had one of the original
test benches from the Aeolian Company's works at Hayes.  It was
huge and rather dilapidated; I wonder if they still have it.

As I remember, it had a standard Duo-Art pump and motor underneath
with an adjustable overload spill.  On top were various suction
outlets, including a number of jigs with wooden flaps covering ports
with kid gaskets, to take whole actions, expression boxes and similar
components.  I think it once had a manometer standing up at the back.
A real test bench!

An old Aeolian employee told me that most parts were checked and graded
at the factory, the best going into the Steinway and Weber pianos.
Action pneumatics were made by women homeworkers (often wives of men
at the factory), some of whom did work of particularly good quality.

Patrick Handscombe
Wivenhoe, Essex, UK