Pezon michel identification and dating
The fingerprints in the Bestfit book can be used to easily identify these movements.
If you click on the pictures a bigger one should pop up in a new window.
The cover plates are often just as unique, it's just that by the time the Bestfit books were introduced, watches with such movements were considered "obsolete". To randomly start looking through references for a movement would be hopeless.
I began this page to try to identify movements like this. The first step in identifying a movement is to determine its size.
Manufacturers altered the appearance of their movements by changing the top plates, but the basic layout remained much the same.
Note that the setting lever screw is an exception to the rule about screw placement, it can be in different places in stem set and pin set varieties of the same movement, or absent altogether if the keyless work is negative set.