This site, International Directory of Musical Instrument Collections,
may be of interest to MMD'ers.  It is not primarily a mechanical
instrument list, but a keyword search under terms such as "Bruder"
does give a few hits, notably on the Waldkirch entry.  For some reason
"Gavioli" comes up empty, although there is a Gavioli entry in the
Waldkirch museum listing.

The URL is  http://www.music.ed.ac.uk/euchmi/cimcim/id/idtde.html

Matthew Caulfield