The contract between Steinway and Aeolian was signed on 20 February
1909.  This contract covered only the American operations of these
multi-national companies.  It meant that Steinway's New York factory
would supply pianos to Aeolian in Garwood, New Jersey, and to no other
player-makers.  The Aeolian-Steinways would be sold in Aeolian dealers
-- which at a stroke doubled the Steinway dealerships, massively
increasing its sales and profits.

The agreement was that Aeolian would take at least 600 pianos each
year.  The process was that Aeolian took unfinished Steinways, added
player works to them and casework trim such as legs, then polished
them.  So, the instruments are a complex mix of the two factories.
I think that Steinway-Pianolas were sold only via Aeolian's dealers,
and not via Steinway's dealers.

So, from some point in 1909 onwards Steinways were fitted with
Pianolas, and later Duo-Arts (which Aeolian called "Duo-Art Pianola
Pianos"; they were all Pianolas).  Up to the Duo-Art launch in late
1913 there would have been a minimum of 600 foot-pumped Pianolas each
year (assuming the numbers held up).  I very much doubt there was a
hard cessation of foot-pump models, it was just a case of what the
customer ordered.  However, in the earliest days of the Duo-Art some
style OP grands are known to have been converted to Duo-Art -- a
giveaway being the lack of half-blow.  This hints that sales as
Duo-Arts dominated almost immediately.

In Europe, Steinway's Hamburg factory continued to supply M. Welte
& Co. in Freiburg, as well as Aeolian's London factory.  I think the
Welte supply process was that once Welte fitted the works the
instruments went back to Steinway for completion.  The Steinway-Weltes
were sold via Steinway dealerships in Europe.

The Steinways supplied to Aeolian in London were finished and sold
the same way as in Garwood, but with one big difference -- that many
(the majority) of Hamburg Steinways supplied to Aeolian in London were
equipped as Pedal-Electric Duo-Arts [PEDA] because that's what buyers
chose.  This continued to the closure of Aeolian's London factory in
1932, but how many Steinways sold in later years is a moot point.

Julian Dyer