Hello,  This is a rather interesting design of cylinder music box.
With the comb in the front and the cylinder in the back, note that
the bass notes (longer teeth) are on the right.  In all other cylinder
boxes, the bass teeth are on the left.  It's called a "reverse comb"
music box.  This was done to differentiate these musical mechanisms
from those made elsewhere because of a trade agreement at the time.

95% of the Rzebitschek movements are small, 2-tune mechanisms, like
the one you have, although a very few were made with 3 tunes.  They
are usually found in the base of a clock or in a small wooden box.

It's difficult to give a value without seeing or hearing it (and MMD
isn't an appraisal service).  But, in general, a mechanism that plays
can go for anywhere from a couple hundred dollars to well over a
thousand dollars.  Factors to consider would be general condition,
restoration quality, music selections, and the quality of the
arrangements.

One of the more significant factors is what sort of music box case
it's in, e.g., movement only, plain wooden box, fancy box, musical
clock, fancy musical clock, automaton.

Regards,

Craig Smith