You might want to call Joe Hickerson at the Archive of Folk Culture at the
Library of Congress (202 707-5510).  I'm sure they're on line, too, but I
don't know the address.  The machine you are talking about sounds like one
of the type that folklorists used in the field to record songs and stories
before tape recorders.  Because the Archive has a lot of discs recorded on
machines like this in their collection, they are familiar with the
machines that made them.  At the library you might also want to contact
the Recorded Sound Section (202 707-7833)--they know about these materials
as well.  Good luck.
Kathy Condon