Well, I've been thinking about the problem of the repair of a music
box comb.  And while I understand that it's a big secret, it's fun
to consider some likely alternatives.

1)  Silver solder comes to mind first.  the old stub and the new piece
are ground off, probably at a bevel to increase the area of the repair.
The parts are bonded with a refractory cement to another piece of
steel.  The whole assembly is heated and the solder applied to the
joint.  Everything is left to cool.  Then the whole comb is heated,
quenched in oil or some other elixir, then heated to blue in brass
filings and quenched again, and finally polished and tuned.  This
is about what we do in clock repair when we bust a part.  Not overly
mysterious.

2)  Soft soldering or some milder sort of brazing would work, too,
if there is enough stock left to add a pin or other reinforcement.
I've seen this done and it seems to work well enough.

3)  I have always been impressed with the stiffness and integrity
that a good spot weld or other resistance weld provides.  To do these,
you merely need to hold the parts together and run a current from one
to the other.  The resistance at the joint causes a heat concentration
there, and the parts soon melt and weld together.  You have to keep the
parts mashed together pretty hard and have a good reliable contact with
a hearty current source.  A music box repairman likely doesn't have
such an arrangement, but he could easily make an arrangement with
someone who has, namely the nearest optician, who resistance-welds
metal eyeglass frames together daily.  You'd likely have to at least
polish if not reharden and temper the repaired comb afterward.

4)  Or you could just buy a new comb (there are probably popular sizes)
from a supplier who specializes in such things.  S. LaRose might even
have 'em, but if there are clock spring specialists, there must be
music-box comb specialists.

Mark Kinsler
Lancaster, Ohio, USA
http://home.earthlink.net/~mkinsler1