Zenith S58

Year: from 1958.
It seems the S58 could have received 3 calibers.
The caliber 120 for a manual version without date.
The caliber 71 (bumper automatic) for the S58 automatic date.
Caliber 71 was produced from 1954 to 1957; 71 runs at 21600 a/h.
At last, the caliber 2542 PC produced from 1964 to 1969 for the last versions automatic date of the S58.
2542 PC runs at 28800 a/h.

We are interested for more information about S58!