Depending on what the problem is that causes the musical movement in
your rocking chair not to work (broken linkage, lack of lubrication,
worn gearing, dead mouse in works), it should be more or less simple
to repair.  Nobody today that I know of is making those rocking chair
cylinder movements, although there seems to be a demand for them.  The
Musical Box Society International gets a half dozen inquiries a year
like yours.

The late Ralph Heintz had a couple of replacement rocker movements
in his warehouse storage before his death this year, but he never got
around to digging them out.  So the best thing I can recommend is that
you remove the movement from your rocker and mail it to a music box
technician for examination, advice, and repair estimate.

It is a good bet that the movement was made by Thorens or Reuge.
Assuming you are in the U.S., there are two California people you might
contact: Tony Ciuffini <tciuffini@cox.net> or Don Caine <mbrcu@aol.com>.
On the East Coast there is Nancy Fratti in New York <musicbox@dreamscape.com>
and Al Meekins in Georgia <al@antiquemusicboxes.com>.

These are only four of many good repair people.  If you tell where you
are located, perhaps one closer to you can be identified.

Matthew Caulfield
Irondequoit, New York