Nancy Fratti, Canastota, New York, has over 1500 music box discs in
stock.  She offers a list for $4.00 or welcomes specific requests by
email: musicbox@frontiernet.net.geentroep [delete ".geentroep" to reply]

Barry Johnson, Menlo Park, Calif., makes new discs for Polyphons and
a dozen other machines.  Barry seems to be one of those Luddites --
luckily a diminishing group -- who doesn't have email.  His phone
number is 1-650-323-5268.

Kevin McElhone <kevin_mcelhone@hotmail.com.geentroep> is in England,
but he ships worldwide and has discs for various boxes.

There are doubtless others selling discs, but these are the three
I can think of at the moment.

Matthew Caulfield
Irondequoit, New York