Scotty,  Here's a 5-step process to fix your music box:

1. Stop playing around with the governor.  If you actually break it,
it will cause a 'run' of the music box and destroy it before your
very eyes.

2. Find someone nearby who knows how to do step 3 below.

3. Have them let down the spring to remove all force from the governor.

4. Then have them take off the governor and send it to Bob School in
Akron, Ohio.  He will reshape the end of the worm and replace the jewel
and that will fix it (if you're lucky).

5. If you're not so lucky, he'll make you a new worm and matching gear
for a very reasonable cost.

6. Re-install the governor when you get it back and you're good to go
for another 100 years.

Regards,
Craig Smith
Upstate New York