Dear Mr. Mike Brooks, I can answer about your wish in 990613 MMD.
In Japan, we can order the custom-made 18-tooth cylinder music box
from a mechanical music museum, and the Hall of Halls can accept
the order from overseas.

   http://www.sannichi-ybs.co.jp/MOEGI/

I made a phone call to Natori Junichi of the Hall of Halls today,
and he said "Yes, we can."

So, Mr. Brooks, you can order the "only one" music box from them, with
your original tune installed.  The price of one piece of the music box
is Japanese Yen 25,000.- (about US$ 208.-) plus shipping charge and so
on.  The box is made of plain woods, but you can order some other type
box, if you pay extra charge.

The e-mail address of Mr. Natori Junichi is <LEA04126@nifty.ne.jp>.
If you are interested in this music box, please contact him.  (He can
speak English.  "Natori" is his family name.)

Murakami Kazuo, Japan