Zenith movements of this era (pre-1940) are identified by their size in lignes. A good number of these movements have the "snail-cam" regulator, which is a trademark of Zenith.
https://www.convertunits.com/from/mm/to/ligne [France]
Differences in fractions of a millimeter may mean it is a totally different caliber. You would need to find an old reference book on Zenith movements. Some of these calibers can only be identified by the position of screws.
This is impossible to see from an internet photograph.
gatorcpa
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