HELP ID OMEGA POCKET WATCH MOVEMENT CALIBRE & PRODUCTION DATE

Can anyone tell me what caliber this is and when it was made?
One site says it was made in 1916
Another says 1919

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Hi Rod, what's the movement diameter?

Calibre 19 measures 42.3mm, later 42.7 calibre introduced around 1911 (42.7mm...)

P

Hi Pete,
Sending a PM.
Rod