1) Borrow an ETD (SAT, Reyburn iRCT etc) and measure the pitches especially in the top octaves. 2) Call Yamaha, perhaps the piano people have the information you need. If not, they'll point you in the right direction. You may have long "wait times", I hope not.
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Patrick Draine RPT
Billerica MA
(978) 663-9690
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