Gil, I don't know what a 1/3 Corvair will produce in thrust.
We made static thrust measurements for our LEU with a couple different props. This was a 1/2 VW producing 29 hp (as measured by the wood bar dyno method);
unknown 54x20, 3120 rpm, 101 lbs
Hegy 54x22, 3090 rpm, 93 lbs. Note, we never flew the 54x20 because it was too sluggish on take-off roll. We found the 54x22 to be much more peppy on ground roll. (was it due to pitch difference, or different mfg, or both?)
I was taking notes as others reported their prop info. Here is what the notes say:
45 hp Casler, Tenn 58x24, 2800 rpm, 170 lbs (unloads during climb, rpm goes to 2950)
45 hp Casler, unknown 58x22, 3050 rpm, 180 lbs
78x92 stroke/bore, Tenn 54x24, 3400 rpm, 195 lbs
78x92, unknown 54x24, 3000 rpm, ? lbs
86x94 Casler, Tenn 58x24, ? rpm, ? lbs (great climb reported)
Keep in mind that static thrust is not a full indicator of performance in flight. A prop could be partially stalled during full throttle static test, producing a lower lbs pull, but as soon as the airplane gets forward speed, it will unstall and start working hard. A prop that is working its hardest at no forward speed may give out as it gets airspeed. I think these airplanes need a prop to be working the best at climb speeds.
Your 1/3 Corvair will have some stroke/bore, maybe close to some of the above, theoretically similar power with similar prop performance.
I know this does not answer your question, but hopefully some help.