I know next to nothing about PAM and there may well be some variations in the movement across the production run.
I have seen some with panerai engraved plate but the examples I've added here all have a different regulator assembly to the one WF have photographed.
I've rotated the WF photo so the regulator is easier to compare with the other examples.
The WF looks different to all the other examples, missing 2 screws and a the regulator(at least what I think is the regulator) is different to all the other examples.