Chuck, thanks for the offer, but the Rev-up 10x4 is just not quite enough prop for the HP IMO. I still have one used Rev-up 11x4 just in case. I used to use Rev-up 10x5's on the HP with good results.
Paul, the leading edges are not blunt, but they are not sharpened like a razor either. The thinning I do is mostly on the cambered side, which increases the camber. This would make the airfoil shape more pronounced, which should create more lift or thrust. I don't know if the theory is correct, but the results I can see. Tom