Hi, I have a collection of several mechanical music machines,
principally Polyphons.  I recently acquired a Symphonion clock
with a Junghans(?) clock.  The Symphonion mechanism works perfectly,
"like clockwork!"  However, the clock has no pendulum (or key).

I wondered if anyone could tell me the type of pendulum I need.
The drop from the hanger to the wooden base is 21 cm.  The dial has
a diameter of 22 cm if that helps.  The connections between the clock
and Symphonion also appear to be mostly missing.

If anyone could give me any clues (or photos) as to what should be
there it would be really helpful.

Many thanks,
Peter Haigh