Unique Door Closer! Vintage San Jose Elevator Co. Hydraulic Swing Door Elevator in Menlo Park, CA

This elevator features a unique type of door closer that I don't think I have seen before on a swing door elevator. It's an "internal" door closer mounted in the door jamb, only visible when the door is open.
Fixtures: GAL black buttons
Year installed: Circa 1964
Date of recording: May 2024