I think it's from the 1930s, the serial number on the back shows:
809950
12511

 

I'm no expert on these vintage chronos, but when them-as-knows turn up, they will probably ask to see photos of the movement, inner caseback, and pushers and crown. Brighter and more even lighting wouldn't go amiss either.

 

THis might help:
https://omegaforums.net/threads/vintage-omega-posting-guide.383/

 

Here's mine with the same 12511 reference. Your has different hands, but dial appears original, Henri Jenneret case is slightly polished but still having the distinctive facets on the lugs, and it should have a cal 156 movement within.