Hello everyone! I've had this 1950s Wittnauer chrono for about 2 years now, but have not been able to find the reference number. I've seen quite a few examples of the exact watch sell in the past years (same dial, hands, crown, etc), but no one mentions the reference. Movement is a Venus 188, if that helps at all. As far as I can tell and based on other examples I've seen, it is not a redial.
Here is a photo of it (from my instagram, please don't mind the filter ):