> I've been told it's difficult to find people to do these repairs.

The best person you could send the singing birdcage to is

Russ MacKay
Goose Creek, South Carolina
jrmackay@comcast.net.geentroep [delete ".geentroep" to reply]

He does _excellent_ work, not only on the bellows but also
refurbishing the top part as well -- and is reasonable with pricing.

Good luck!

Nancy Fratti - Nancy Fratti Music Boxes
Canastota, New York
http://www.nancyfrattimusicboxes.com/