I talked to Hall and Phil Hill about the 2E and 2F cars while they were over here at Goodwood. Incidentally, both were used in 67 - the 2E in Can Am, the 2F in FIA Sports Car racing in Europe.
Hall also pioneered the use of an automatic transmission in a race car and left foot braking which all the guys now do with the F1 style computer gear boxes or sequential crash boxes common in sports car racing. Since he no longer needed a clutch pedal he was able to put the wing control pedal in its place. Hill told me it was actually fairly easy to drive once you got used to it because the pedal only really had two positions - on and off. If you were accelerating you put your right foot all the way down on the gas and your left foot all the way down on wing to trim it out. When it came time to brake, you took your left foot off the wing and used it on the brake so that you increased the downforce and could still modulate the throttle if need be. Very simple cool stuff - a hallmark of Hall!!