Dating your omega watch
However all the parts, including the plates, are fully inter-changeable.Please use the menu above to explore the various Omega f300 models in the Constellation, Seamaster, De Ville, Geneve and Speedsonic range of watches.The non-chronograph f300s must have been produced in the tens of thousands and are often seen on a popular auction site today.The Omega version of these movements differ slightly from standard ESA 9162, 91 movements in having copper plated plates (see image on left) throughout the movement; all other watch manufacturers kept the ESA-supplied nickel plated plates (see image on right).I’ve also written a page about Omega case numbers and how to date your Omega f300 watch.Finally, for those interested in what might go wrong with their f300, an “Issues” page.Generally, the push button at 2 o'clock is to start and stop the chronograph function.
Older Omega watches may only have the serial number on the inside of the watch, which may require a jeweller or independent watch maker to open the case back.
Until recently when Omega started to put the serial number on the lugs, the serial number is usually found on the movement so it requires that the caseback be opened or the movement taken out..
Never the less, if you have the number here is a chart for dating your Omega...
the problem with using Ryan's chart (or any chart for that matter): Every Speedy Pro has a unique number on the escape wheel bridge.
(On later model Speedy Pros, this number is also engraved on the back of the lug.) Most refer to this as the movement number but more accurately, this number should be called the "escape wheel bridge" number.