Unless you have old catalogs or advertising, reference #s are hard to come by
Won't be easy to find. Why is the ref. number important to you?
No reason to believe that it isn't legitimate. During that period, date complications were generally favored, and that probably explains why only that version was shown in the catalogue.
I wouldn’t say it’s rare but it’s an uncommon version. There’s a couple of versions of that dial. Zenith didn’t put ref numbers on their watches but did list them in catalogs and ads. I think ? these came out around the time of the Victorious. Zenith bought Martel who had a Victorious model as well.
https://omegaforums.net/threads/zenith-victorious.87364/
These are also based on the Martel 25xx movement if I remember correctly