I believe it’s the first and last time Zenith used a non in house calibre, brought out under a Monsieur Philippe DuFour, perhaps you’ve heard of him? He’s over at Rolex now 🙂
More importantly, you have the strength/confidence to venture trying new things even while knowing there is the possibility of ‘error’…this highlights to me a strong artistic spirit (and experience too) where always venturing deeper/farther to reveal new ...