Regarding friction in music box governors, after you have done what is
suggested in these various posts you can also add a lubricant modifier
that will greatly reduce friction.  It is an extreme pressure additive.

GM ACDelco Limited Slip Axle Lubricant Additive is an additive used in
General Motors limited-slip differentials of the type that use friction
clutches.  It is added to the rear axle to reduce friction and eliminate
differential clutch chatter.  Just mix in a small amount of this to the
lube you are now using on the governor.  You will be amazed.  It is
GM part number 88900330, generally available from GM dealers, auto parts
stores and Amazon.

Wally Donoghue