My daughter-in-law has a Thorens music box made in the early 50's.
It plays black disks that look roughly 5 inches in diameter.

Her daughter overwound it and the spring went 'sprong'.  It seems
to be broken near the middle of the coil.  She wants to know if it
can be repaired.  Nothing about the music box is elaborate but it has
sentimental value.

Bill Finch