Dear Ruth,  The mechanism in the rocking chair is a ratchet mechanism
that is no longer available.  However, there is a replacement mechanism
made in Switzerland by a friend of mine who will be visiting the USA
later this month for the Musical Box Society Annual Meeting.  If you
are interested, I can ask him to bring 3 of these mechanisms for you.
I'm sorry, but I don't know the price.

Beatrice Robertson