Came across this site which gives good info on many watch movement and it is also links to Ranfft.
Very helpful if you want to find out more about a specific movement and many of its main parts (mainspring, stem, beat rate etc).
Not complete but many lesser known movements included.
It also includes info on non-watch items such as computers, radio, tv etc.
German site but English version can be selected.
http://www.christophlorenz.de/sitemap.php