From Dr Ranfft’s pink pages this looks to be a cal 220. 15j, subseconds and 23.4mm handwind all match up. Production from 1935 into the war years. From the position of the regulator it requires a service. If you tell us where you’re located you can get some recommendations for a watchmaker.
Not a 23.4. (the bridges design is different on the 23.4), but probably a 23.7. What size is the caliber inside?
Case is not original but a later non Omega replacement.
Hour hand is a replacement also. The crown is something like 25 years younger than the caliber.
From Dr Ranfft’s pink pages this looks to be a cal 220
Either way, I love the look of it.
Sorry - no it is not.
Caliber is 23.7
edit - @Tire-comedon told you while I was writing... he is always a bit faster 😀