Patek Philippe is only now being recognized for its mid-20th century groundbreaking research into the development of solar energy and its use in powering timekeepers. The stunning case of this clock is made in rosewood as confirmed on its Extract From the Archives. Only a handful of rosewood Patek Philippe clocks are known to exist and this is the only one known in the ref. 907 configuration.
To learn more about Patek Philippe electronic clocks, please see this Collectability In-Depth article, and this Collectability YouTube video.