Can anyone tell me the rough dates when each Zenith buckle style was used? | WatchUSeek Watch Forums
![CHRONOMASTER EL PRIMERO - Orologi Zenith linea CHRONOMASTER - concessionario ufficiale Zenith a Viareggio. CHRONOMASTER EL PRIMERO - Orologi Zenith linea CHRONOMASTER - concessionario ufficiale Zenith a Viareggio.](https://www.pasqualidomenici.it/wp-content/uploads/2022/07/03_2150_400_53.m2150.jpg)
CHRONOMASTER EL PRIMERO - Orologi Zenith linea CHRONOMASTER - concessionario ufficiale Zenith a Viareggio.
![New Zenith Defy Skyline Skeleton: The 1st Skeleton Watch At 1/10 Of A Second | Italian Watch Spotter New Zenith Defy Skyline Skeleton: The 1st Skeleton Watch At 1/10 Of A Second | Italian Watch Spotter](https://italianwatchspotter.com/wp-content/uploads/2023/01/iws-nuovo-zenith-defy-skyline-skeleton-vintage-advert-el-primero-1.png)
New Zenith Defy Skyline Skeleton: The 1st Skeleton Watch At 1/10 Of A Second | Italian Watch Spotter
![CHRONOMASTER EL PRIMERO OPEN - Orologi Zenith linea CHRONOMASTER - concessionario ufficiale Zenith a Viareggio. CHRONOMASTER EL PRIMERO OPEN - Orologi Zenith linea CHRONOMASTER - concessionario ufficiale Zenith a Viareggio.](https://www.pasqualidomenici.it/wp-content/uploads/2022/07/03.2040.4061.52.C700.jpg)