I'll agree with Nic on the first picture, TB may have been looking at hinging and moments of inertia on the ailerons. I believe the second and third sketches may be for calculating bulkhead area, ((a "section cut") at a particular fuselage station. As far as the large circle, Tom may have just grabbed a reasonably clear sheet of paper and started sketching for some other idea.

Bottom line is who knows for certain except for those who may have had contact with Tom during the design/build process.

I think I recall seeing a mag picture caption of the airplane as the "Lateral Area Special"?

Either way, as a rookie to RC and 13 years old at the time, this airplane stood out among the others at the 1965 Nats. Funny I can't remember the others except this one.