Hi,  my problem is not about mechanical music, but it's related to
refinishing pianos too.  When I laid my hardwood floor two years ago,
I didn't have the energy to varnish it.  So it's quite dirty now.

I'm about to varnish and sand it (most of the superficial dirt will
be sanded away) but some grease and oil has penetrated the wood.
I'm planning to use a water-based varnish so no trace of grease should
remain.

What chemical should I use to get the grease stains (dissolve) out
of the wood ?  Ammonia ?

Thanks & Best regards,
Patrick Boeckstijns
Brussels

 [ I face a similar problem in a nickelodeon: lubricant in the
 [ over-filled gear reservoir has dribbled to the floor of the
 [ case (for 80 years, it seems!).  -- Robbie