Links to other collections covering more or less the same objects and period have not been found. Any suggestions in this regard would be highly appreciated.

Apart from commercial companies selling music boxes, with the exception of Reuge, there is not a lot of information available on the internet on the companies making the music mechanisms and/or the music boxes or musical toys, even after extensive 'Google-ing'.
It is even more difficult to find information on Japanese producers, at least in the English language. Often music mechanisms/boxes are only a small part of the business, as with Sankyo, mainly an electronic components company. Or companies have disappeared or been taken over, as Otagiri (Mercantile Comp. Inc, a South San Francisco CA company, but ordering the objects made in their name in Japan) in Sept 1994 by Enesco Corp, Illinois.

However, there is an abundance of museums in the USA, Europe and Asia specializing in mechanical music from mainly the 19th and some of the 20th Century. The MBSI site has an impressive list of those museums (but not really for musical toys), with no need to repeat it here, except a few.

The link suggestions hereunder, therefore, refer to some present day producers, some museums and some general information.

www.reuge.com
Switzerland
Also provides a link to the CIMA museum.
Reuge, still active, has taken over a number of producers of music mechanisms, as Bintem, Paris France (mechanical singing birds), Eschle, Melodies SA (Thorens, disc boxes), Lador, Guendet and Intersio Italy (earlier producer of music mechanisms for Reuge).

www.sfmusicbox.com
San Francisco Music Box Company. Probably the best known seller of music boxes in the USA.

www.enesco.com
A large supplier of music boxes under their own name with many lines made all around the world (at least in the past).

www.safeshoppingnetwork.com
Some safe tested links to music box web stores.

www.ebay.com
www.yahoo.com
Best known auction sites for music boxes and musical toys.

www.mbsi.org
Musical Box Society International, USA
Links to similar organizations in many other countries, is a non-profit organization dedicated for the preservation of automatic musical instruments. Has links to related museums in the USA and abroad.

www.si.edu/scmre/takingcare/musicboxes.htm
Smithsonian, also links to museums, orgs, etc.

www.musees.ch
Swiss museum link, where many of the music mechanism makers were originally concentrated.

www.museumspeelklok.nl
The Netherlands
Click English flag for English language version. Many large pieces, street organs, etc.

www.worldslargesttoymuseum.com
Branson, MO, USA
Also includes musical toys.

www.spielzeugmuseum-seiffen.de/Germany
Exhibits musical toys specifically from the Erzgebirge region (many wooden toys).

www.collectinsure.com
Insures valuable collections of all kind of objects since 1966.

www.handcranktoys.com
Mainly Jack-in-the Box and some other handcrank musical toys.