Dear Fredy,  Greetings from Upstate New York!  In regard to your
dilemma, have you tried contacting QRS to see if they have a fix for
your problem?  The QRS Pianomation system that I was familiar with
back in the 1980s, as I recall, didn't have a synthesizer within it.
Instead, the music disc contained what was in essence a CD track of
the accompaniment to the piano digital information.

I further recall, with the [competing] PianoDisc system, you were
able to adjust the internal synthesizer (that is, in the models so
equipped) to match the tuning pitch of the piano.

Should you go with restringing the piano, make sure the piano is
capable of withstanding the additional stress of the added tons of
pressure that will be created by pulling the pitch up to A 440 Hz.

 [ I think that's why new strings might be installed, of smaller
 [ gage than the strings currently in the piano.  -- Robbie

One other idea is to see if the Pianomation unit has a MIDI-out
connector.  Perhaps you could disable the internal synthesizer and
instead plug in an external synth so that you will be able to adjust
the pitch of the accompaniment to match the pianos pitch.

Hope this helps,

D. F. Rowe (Bronx, N.Y.)
Newark Valley, New York