John,  While it is theoretically possible to replace a missing comb on a
cylinder box, the reality is that it's a long shot.  The tuning on all
cylinder box combs (except the interchangeables) is entirely different
from box to box.  You mentioned that yours had 'one removable cylinder'.
Does that mean that it IS an interchangeable but only has one cylinder
now, or does it mean that it is a stationary cylinder box and you can
unscrew the cylinder bridges?

If it is an interchangeable, there is a possibility of finding an
identical box and copying the comb from a 'loaner'.  However, making a
comb can be cost prohibitive.  Usually about $2,000 and up, depending
upon the size and complexity of the comb.  If, however, the box is NOT
an interchangeable, you're basically out of luck.

If you'd like to talk further about this call me.

Nancy Fratti - Panchronia Antiquities
PO BOX 210 - Whitehall, NY 12887-0210 USA
518-282-9770  or fax: 518-282-9800
Disc & Cylinder Musical Boxes - Musical Box Restoration Supplies