curved date ring and case back for Zenith El Primero A788

Hello everyone,


I am restoring a Zenith El Primero A788 fitted with the calibre 3019 PHC and I am looking for help identifying and sourcing two parts:

• the correct original A788 case back;
• the original curved or dished date indicator ring.

The date ring originally fitted to my watch is visibly profiled rather than flat. The outer numbered section sits at a different height from the inner toothed section. I have compared it with a commonly available flat 2557/1 ring, and the flat version does not fit correctly.


I have attached:

1. a comparison between the flat 2557/1 ring and the original A788 ring;
2. a side view showing the curvature of the original ring.

I am trying to establish:

• the exact part reference of the curved A788 date ring;
• whether it was specific to the A788 or used in other early 3019 PHC references;
• whether the 3019 PHF date ring, possibly 2557/6, has the same profile;
• whether 2557/3 represents an earlier curved version;
• whether anyone has an original ring, case back, donor movement or donor watch available.

Used or NOS parts are both acceptable. I am located in Poland but can purchase worldwide.


Any period parts catalogues, workshop documentation, photographs or measurements would also be extremely useful.


Thank you in advance.