Hi,  It's hard to comment on repairs to the case without seeing the
damage.  In general, it can be done and if done well, it shouldn't
affect the value too much.  If you're talking about case repairs, only
I would recommend taking it to someone who repairs wood and removing
the music box mechanism first.  Ord-Hume covers repairs to cases in
"Restoring Musical Boxes and Musical Clocks" and treats the subject
quite well.

The tune card states that the box is a "mandoline".  I hope that I'm
not disappointing you in that the picture of the comb shows a regular
box, not a mandoline box.  A true mandoline box is quite rare and very
expensive.

There are two major signals to point out a mandoline box: the first
is the angle of the teeth.  To achieve a mandoline effect, you need
somewhere between 6-8 (even 10!) teeth for each note.  This will give
you many teeth and a very small angle of the teeth (usually the bass is
steep, the treble is shallow).  The second way to identify a mandoline
box is that you can visually see on the cylinder a fast repetition on
the same note--this will appear as several pins in a row (repeating
across different teeth) at a fast rate.

My third comment is that the "garnet or ruby" costs around $15 for that
size.

Finally about playing a music box that you're unfamiliar with.  This is
a subject that I've been thinking about writing on for a long time, now
I have an excuse.  In general, if you're in a store and you see a music
box that you'd like to hear, ask the salesman to demonstrate it for
you.  You don't want to be blamed if the governor isn't working.  On
eBay you don't have that option so here's a good way to start building
confidence that it works.

First step: remove the power of the spring.  This is the first step
before you do anything else to try out the box -- even if you've heard
it before, it may have been damaged in shipment and you want to try it
out before you trust it.  To "bring down" a spring is not that
difficult, but it takes a little planning.  I'll explain the step for
a lever wind box, a keywound is a little simpler.

The spring has a ratchet gear that has a pawl (finger) on the bottom
and a second pawl on the lever.  To bring the spring down first you
need to remove the Geneva stop (if there is one).  The Geneva stop is
a small gear, usually on the side of the spring (facing the comb) that
stops how many times you can wind or unwind the spring.  The problem
with trusting the Geneva spring is that if you get into a "run"
condition in any step, it will simply snap the finger off the Geneva
stop.

Next to unwind the comb you need to pull the lever forward 1 click of
the spring, then release the lever just enough so that the ratchet gear
is being held by the bottom pawl not the top one.  In that position,
release the top pawl and pull the lever forward -- there should be no
tension on the spring when you pull it forward in this way.  (I use
a dentist probe to work the pawls).

Now you need to slowly bring the lever back the top pawl clicks once,
pull the lever forward slightly (transfer the tension from the bottom
pawl to the top), push down (again with the dentist's probe) on the
bottom pawl so it will not catch and slowly bring the lever back.
Repeat this for as long as there is any resistance on the spring.

Okay, good, you've taken all the tension from the spring.  If you know
what you're doing, I would recommend removing the comb for the first
few runs of the cylinder.  Make sure that the cylinder is in the stop
position before you do this!  In any event, if you are sure that the
spring has no power, put the music box to "play" and turn the cylinder
by hand.  It should be slow to move and you should feel the resistance
of the governor holding you back.  In addition, you should see the
butterfly spinning.

At the end of the cylinder, I always wind one turn, as you don't want
negative pressure on your spring either -- with negative pressure, you
can either un-hook the spring from the cylinder barrel (a nightmare but
not tragic for someone who knows what they're doing) or worse yet, you
can break the spring.  A large spring can generally tolerate one turn
of the cylinder, but I don't recommend more.

After you wind one turn, try to let down the spring to see if there's
any tension.  If no tension, then wind an additional turn -- you'll
feel when you get to the "zero" point -- keep the pressure there until
you're satisfied that the governor is working.  Once you have faith in
the governor, you can try to run the music box.  Again, I recommend
doing this without the comb.  No comb means no damage.  If you can run
the box with no comb, wind it all the way and let it play down to nothing.
Don't wind past where you feel comfortable because you removed the
Geneva stop from the spring, remember?  Wind it and let it play several
times until you're comfortable that it's working before trying it with
the comb.

Remember that nothing is fool-proof, Murphy loves to trick you and
please don't be mad at me if you follow my instructions and still do
damage.

I have a keywound mandoline box that had a problem with the first gear
of the governor.  Someone soldered a pin in place of the original
pivot.  I tried it by hand and the governor held.  As soon as I wound
it 1 turn and let it play, the box played about 1/4 song and then
released the rest of the tension in a run.

If I had wound more than 1 turn I would have had extensive cylinder
damage, broken teeth and tips.  As it was, I only had a couple bent
pins on the cylinder that I was able to straighten out.

Good luck.  If you have any questions, please feel free to email me.

Eliyahu Shahar