Dear Sirs I'm a Norwegian collector of vintage Omegawatches. I have this Seamaster, Ref 2846. It has a cal 501, but serialnumber 34 mill (1972). The serialnumber is engraved (or stamped) on the barrel bridge. As far as I have checked, this barrel bridge will not fit any later automatics. Or vica versa. The calibers 501 to 505 was produced until around 1959-60, and was then replaced by the 550 series. Do you guys have any idea on how this can have happend? Can it be a misprint ? Thanks for your time! Kind regards Dag Braanaas, Oslo, Norway