Great picture (again), Lou. That must have been after the time of bi-planes where wings were above both the front and rear axles. It's striking how spindly the wing struts were. They didn't appear to have an appreciation for the loads those wings generated. That became painfully clear when they broke on Graham Hill's and Jochen Rindt's car later on the 72, I believe.
I think it's interesting that the Chaparrals were running wings mounted on the rear uprights for two years before the F1 guys decided to try it. The Chaparral wings were adjustable under driver control and my memory was that the F1 wings were also controlled by the driver - at least at some point - becaues after they started failing on the F1 cars (don't remember if other cars besides Lotus has a problem), the FIA banned "movable aerodynamic devices" on all race cars which outlawed the movable wings on the Chaparrals. If they were controlled by the driver, I don't know that I ever knew how it was accomplished.
Sorry for wandering a bit off the topic of the picture, but that era was pivotal since aerodynamics and stickier slicks came together and transformed all road racing!