You don't have to change over to plastic keytops -- you can get used
ivory from Schaff Piano Supply Co., tel: 800-747-4266, or from APSCO:
tel 800-457-4266, part number 361015 heads & 361016 tails.

Remember originally there were over 20 different shades of ivory, and many
were cut in different widths and lengths, so if you order, get more than
you need.  Also you will need some ivory clamps and glue wafers.

Most discoloration to ivory (if it's not a different shade) is layered
-- meaning you can sand it away.  To sand your ivories, once they are
attached to the key, get a piece of 1-foot square glass or a mirror and
back it with wood.  Put a piece of #240 wet/dry and sandpaper on it and
sand the ivory key while applying downward pressure.  #240 grit will get
most imperfections out.  Then work your way up to #400 then #600.  After
that it's to the buffing wheel with buffing compound.  If you need more
info contact the Piano Technician's Guild -- they have some in-depth
articles.

The best plastic keytops are from Yamaha.  Now you can try the whole
process of putting them on yourself or you can send them out to be done.
The guy I use is:

    Ted Oberhaus
    Seneca Piano Key
    4977 Frontenac Rd.
    Trumansburg, NY 14886
    tel:  607-387-3095

His work is truly great, with beveled edges on all sides (and he uses
Yamaha keytops).  As far as keeping the plastic non-greasy, it gets that
way because it isn't absorbent.  Try using Cory Keytop Cleaner.

Charles Flaum, RPT¶
CMF Piano Accessories¶
cmf@infi-net.com    www.infi-net.com/pianostuff¶
1-800-792-4457