13.5cm Super Yashinon Viewfinder comp

This is s total mystery to me. It is obviously a viewfinder made by Yashica but I've never seen one like it before. Designed for use with a 13.5cm Super Yashinon lens (presumably) what is truly unusual is the mechanism to raise or lower the angle of the finder. It also has a focusing ring that moves between 3ft (0.9m) and infinity. Weird or what...?

Done