It should not be forgotten that a significant contributor to the resurrection of the El Primero in 1984 was the mighty Rolex Watch Company, which had never jumped on the quartz bandwagon. At this time the Rolex Daytona Cosmograph, a manual-wind chronograph, was powered by the iconic Valjoux 72. Rolex wanted to go automatic ("perpetual" like its other watches), and so sniffed around Zenith, who'd produced the best automatic movement in the El Primero. They closed the deal, and so Zenith supplied its movements to Rolex for the Daytona from 1985-2000, greatly assisting Zenith in resuming its own production.
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Ironically, the history could have been very different. In the midst of the “quartz-crisis”, production of the El Primero ceased. Charles Vermot, an engineer working for the company at the time, chose to store the tools and drawings necessary for El Primero production, preventing them being destroyed. A few years later, under new ownership, and thanks to Vermot’s actions, El Primero production recommenced.
