The correct indentification of European watch movements is one of the most difficult of tasks faced by watch collectors. This reference, offered by Ranfft Watches, is perhaps not definitive, but is an excellent place to start. A warning is necessary – patience is necessary and a willingness to work with ligne measurement is a must (metric measurements are also included). I hope that you find this helpful.

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&&2uswk]