Here is a link to an article (and a podcast) related to a meeting with Ephrem Jobin the designer of this 135 movement, when he was 100 years old.
This comes from the site "Forum à Montres (FAM)" and is proposed by ZEN, an authority when it comes to Zenith watches.
It's in french.
Hope it will be of interest notwithstanding it is in french.
Moment historique sur FAM. La rencontre exceptionnelle avec Ephrem Jobin