Hi Dave...nicely done on the shot
P-40Q, proposed production version with 6 guns. Never built.
Even with these modifications, the P-40Q was still inferior to modern fighters and the project was cancelled.
Twin P-40
A single photo exists of a P-40 with two Merlin engines mounted on top of the wings over the landing gear. The apparent serial number, 41-13456, is from a P-40C, however, the canopy is from an early Hawk 87. No other photos of this aircraft are known to exist, and it's likely to be a joke done by ground crew, with the numbers on the tail being 123456. [1]
https://en.wikipedia.org/wiki/Curtiss_P ... k_variants