Here's what I know about today:

Elgin:
http://elginwatches.org/databases/elgin_sn_intro.html

Waltham:
http://www.waltham.ch/cgi/waltham/search.asp
http://www.nawcc-info.org/WalthamDB/walsernum.htm

Hamilton, Hampden, Rockford, South Bend:
http://www.nawcc-ch149.com/pw_dbresearch.html