That's really interesting, Dick. I remember seeing this back in those days, but didn't know it was your idea.

Also, I hadn't thought about the pitch issue... Always assumed this was done with some kind of a sliding servo tray. (like some people use for elevons)

I recently attended the Don Lowe Masters, and was reminiscing with Ivan Kristensen about the days when pattern guys were getting a little too "gadgetized"... variable pitch props, flaps, dive brakes of different sorts, inflight mixture controls, etc.. I think that, for the reasons you mentioned, they're all glad to be back to basics, control system-wise.

Anyway, now I finally get to say to the person (you) who came up with this idea... "Cool!" Something like this could be used today, to create B2-ish split-drag surfaces, dive brakes, or other interesting control functions. Thanks for sharing the photos with us.