John McClure asked about polishing ivories. I don't necessarily know
the "proper" way to do it but I have done it and was been pleased with
the results. The last one I did was the Steck Duo Art that is in my
living room. When I received it to rebuild, the ivories were in fairly
good condition (only a few chips) but they were GROSSLY blotchy yellow.
To get the ivories back to white, I sanded them down, starting with a
medium-fine coarseness, to get through the yellow. To keep them flat,
I placed the sheet of sandpaper on a piece of thick glass, the sanded
each key individually by moving the key over the sandpaper.
I worked my way through finer and finer sand paper until I got to the
300 to 600 grit range, then I polished them on a jewelers polishing
wheel. It was a cloth type wheel, about 6" in diameter and 1" thick.
I used several grits of jewelers polishing material, again working my
way down to the finest level. The main problem I had was to make sure
the corners of the ivories, especially the sharp notch, didn't wear
down more than the rest of the ivory, causing it to not be flat.
I found this process to be extremely time consuming. I could have
replaced the ivories with plastic in a fraction of the time I spend on
the ivories. But, if I did that, I wouldn't have a nice set of
ivories on my piano today!