Hi Dave & Carol, 

"People most recognized for the repair of mechanical singing birds?"
That kind of depends on where in the world Waldo is with his bird cage
and what's wrong with his Tweeters!

I do some general bird box and bird cage repairs & restorations:

Don Caine - Proprietor, The Music Box Repair Center Unlimited
24703 Pennsylvania Avenue
Lomita, CA 90717-1516 USA
tel.: 1-310-534-1557
email: MBRCU@aol.com
http://www.musicboxrepaircenter.com/ 

But I do farm out, or refer the following other folks for complex jobs
or those requiring parts to be re-created, or birds to be fully rebuilt
and re-feathered. (In no particular order or preference):

Russ MacKay - Birds R Russ
257 Okehampton Drive
Goose Creek, SC 29445-6610 USA
tel.: 1-843-879-9447
email: jrmackay@comcast.net

Ronald Schmuck - President, Nickelodeon Company
R.R. #4, 1 Minto Pines Road
Mount Forest, ON Canada N0G 2LO
Shop: 1-519-261-0686
Cell: 1-519-261-0154
Email: Nickelodeonco@gmail.com
http://www.nickelodeonco.com/ 

Brittany Nicole Cox - Memoria Technica
Seattle, Washington
tel.: 1-206-617-5799
email: bcox.horologist@gmail.com
https://mechanicalcurios.com/ 
 
MMM Mechanical Music Works Manufaktur GmbH
Rheinallee 7/8
65385 Rudesheim am Rhein, Germany
Phone +49 (0)6722 2038300
Fax +49 (0)6722 2038301
email: jens.wendel@smmk.de
https://www.musicboxworld.eu/ 

Good luck & best wishes for a Happy & Healthy 2021

Most sincerely,
Don Caine