Steve,
My opinion is that if you can document that the drawing you presented existed before Dec. 31, 1952, a model built to those sketches would be OTS legal.
Attached are the PAMPA OTS rules. Refer to para 3.0 for Model Requirements.
BTW- That is a super cool design and you would be a rock star at any OTS event in my world.
Jim Hoffman
The article by Joseph Wagner, "Stunt Outlook for '51" including the 1/2 page drawings shown above was published in the March 1951 issue of Model Airplane News, covered 5 pages, starting on page 9. Flaps were fairly new at that time. Here is what Wagner wrote about flaps:
"What about flaps? Well, let's put it this way: a perfectly good stunt model may be had without using flaps (witness the Senior and Open Stunt Winners at the '50 Nationals), but performance can be bettered with them. The reason for this is that deflected flaps change the symmetrical airfoil to a lifting airfoil (the lift actin either upward or downward, depending on whether the flaps are down or up) and this lift, acting in conjunction with the elevators, permits tighter maneuvers without stalling. To be fully effective, flaps should be full span, about 25% of the wing chord at their widest point, tapering to the tips to avoid tip-stalling the wing. Flaps should move opposite to the elevators, and their movement must never exceed 30% of the elevator movement."
Wagner extols the virtues of thick airfoils "with rather sharp leading edges", giving the coordinates for both the NACA 0018 and NACA 0025 airfoils. He also suggests a "15% symmetrical airfoil" for the stabilizer and elevators.
So here is a design in March, 1951, for a 64 in span, 600 sq in area, "powered by a 29" and a weight of 30 oz, with an NACA 0018 airfoil.
This would make a fantastic OTS model. It is certainly OTS legal by PAMPA rules, even if one was never previously built. One problem with it is the flap penalty. So, who is the first to show up with a 600 sq in, 18% wing section, good looking OTS ship, inverted cowled engine, that weighs 30 oz? Hmmm.