Knowledge on my Zodiac

[Dexter]

Hello!
I've just joined the forum trying to learn more about a Zodiac I have, see photo.
I think it's from the 50's but could be earlier. Dimensions are 21mm x 21mm, lug width 15mm,
Stainless steel back, Zodiac Ltd, Le Locle.
I'd be very grateful for any information anyone has on it.
It's not for sale, but I would like to learn more about it.
Many thanks, D

[Butch]

Yes, I would say the 1950's. Is there a serial number on the back you can share?

[Dexter]

Hi,

Is there an explanation to interpret the serial number, I'd prefer not to share it if you don't mind.

Thanks, D

[Butch]

Sorry but no. And you don't have to.