Now I'm not even close to knowing very much about musical boxes, but
in case my opinion might contribute something to this query, I would
like to say that under normal circumstances, of two fully working boxes
both with minor case damage, I would opine that the Mira would be the
more collectible of the two instruments.

Of course, musical tastes vary and there will be people who prefer
the sound of the Regina to that of the Mira, but generally speaking,
because the Mira is scarcer and highly renowned for its richness and
quality of tone, it seems to me that the Mira would win.  It does very
much depend on whether the musical box is being bought for its acoustic
properties or its value retaining properties, though if bought for
musical use then really the question is "Which do I prefer to listen
to?"  (Or in this case perhaps it's "Which does my wife prefer to
listen to!")

This scenario, though, is a little unclear.  Are both boxes single or
double comb?  A double comb box usually has a more attractive sound.
Do both come with a similar quantity of discs?  Are they both a similar
disc size, e.g., 11-inch?

In addition, we have the information that the Mira is missing two
teeth and quite possibly several gearwheel teeth.  These issues are
not impossible to rectify but they will add considerable cost to the
purchase price, and will take time to complete, which may rather defeat
the object of buying, namely, a gift.

If both boxes have the same comb configuration, similar size, similar
number of discs, and price, I'd actually be much more inclined to go
with the Regina, as it apparently works well, and may be in a nice
original condition.

Nicholas Newble