I didn't mean it was a lady's watch - I meant the movement could have been originally intended for a lady's pendant watch. When wristwatches first bacame popular around WWI, companies adapted what they had to fit the bill. Larger pocketwatch calibers made wristwatches that were too clumsy, so the existing smaller movements were put into use.
The hallmark (the lower cased "r" in the upside down shield) tells me the case was made in 1916, which completely jives with the information we have.
Judging by the overall 32 mm size, and the placement of the click for the ratchet wheel you have a 12 ligne (27 mm) caliber S 7-16 p. The only thing I see different from my reference material is that the mounting screws are in a different spot, but Omega did drill those holes in the position yours are for many of their calibers, usually the larger 15 ligne versions - of which the NN S 7-17 p is the larger sister movement.
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