"The Disc Musical Box Book," by Graham Webb, Faber & Faber, 1971,
is considered to be one of the premier books on the subject.  Out
of print for many years but available at most used book dealers.

Another outstanding resource is "The Musical Box, A Guide for
Collectors," by W.J.G. Ord-Hume, 1995.  The book is a compendium
of everything related to musical boxes.  One chapter is devoted to
disc models.  Out of print.

Angelo Rulli
St. Paul, Minnesota