The Champ I owned also had the remains of that system installed under the panel. Nobody in my circle had any idea what it was for or how it worked.
The neatest system for an plane with no electrical system consists of an ordinary drill motor mounted on the engine. It has a gear drive to turn the prop and a cockpit control to activate it. You could carry a few extra charged batteries if you were planning a long day. I believe that it was only approved for the T-Craft BC12.