Hello Mike -- The "Stadtmuseum" has a permanent display of musical
instruments and explicitly mentions some mechanical instruments on
its web site.  Although I live near Munich (some 20 miles away)
I must confess I've never been there, though.  Re the opening times,
the web site says:

  "Auf Grund der angespannten Haushaltslage gelten im
  Musikinstrumentenmuseum eingeschränkte Öffnungszeiten:
  Di.-Fr. 12:00 bis 18:00 und Sa. und So. 10:00 bis 18:00 Uhr."

  "Because of the very limited budget, the museum for
  musical instruments has reduced its opening times:
Tue-Fr 12-6 PM, Sat & Sun 10 AM-6 PM, closed on Mon."

If you have time, there is a new museum for mechanical music at
Beilngries, some 150 km north of Munich.  I think it is open only
on Sundays, or if you arrange a visit.  I think there was something
in MMD when it opened...

Regards
Harald M. Müller

 [ "The Polyphonshop", Beilngries, proprietor Marcus Pregler, visit
 [ http://www.thepolyphonshop.com/  and see the MMD article at
 [ http://mmd.foxtail.com/Archives/Digests/200404/2004.04.27.01.html
 [ -- Robbie