Hi Doug, Greetings from The Bronx!  Have you serviced the spring barrel?
How about the star-wheels?  One or both together can be the problem.

As in wind-up phonographs, over time the grease inside the spring barrel
can dry out to about the consistency of paste, or worse.  This is what
causes the rattling sound as the spring unwinds.  This can also happen
in disc music boxes.

Now add to this the possibility that the star-wheels are in need of
cleaning and lubrication.  And if the star-wheels appear to be sluggish
when manually turned, the more notes that are called upon to play at any
given moment, may be the cause of the hesitation and jumping of the disc
during play, each additional note adding more drag.

If you do service the spring-barrel, it is not necessary to remove the
spring itself, just soak and flush out the old grease and replace it
with a good lithium automotive grease, as it is less likely to dry out
and become a pasty mess in the far distant future.

And if there is a governor, clean this also and lubricate this with
a light oil, such as sewing machine oil.  (This can be procured from
Nancy Fratti in Canastota, New York.  Check her website!)

Hope this is of some help.

D. F. Rowe
Bronx, New York
fredsorchestrion@aol.com.geentroep [delete ".geentroep" to reply]