Tascione

This link is to a database that shows the movement , explains the differences and variations, gives some of the history and identifies things like the correct mainspring and balance staff on the original. many different languages, I think it is a danish site.

http://www.ranfft.de/cgi-bin/bidfun-db. ... ft&0&2uswk

Tukat

It is indeed a nice site with pictures of most (modern) movements. I use it regularly to lookup movements and find similar movements. The references for staff, mainspring and stem are for the "Flume" catalog, which is similar to Best-fit and others. You can use them to do a search for other movements having the same staff, stem ...
FYI it is a German site.

Jan