The sliding levers mechanism is for a "Zither" or "Mandolin"
attachment.  A roll, a little less than the size of a smaller lead
pencil of silk glued onto paper, then is glued onto the underside of
each of the mechanisms which slide over the combs.

As far as the popping of the disc, you might check the disc
projections to make sure that they are not damaged and secondly, turn
each star wheel to make sure that none of the tips are bent slightly
causing the wheel to jam which subsequently will cause the disc to pop
up over the stuck wheel.  A fine screw driver will work and make sure
you turn the star wheel at least a full rotation -- and make sure that
you do not turn it backwards!

Greg Filardo