A lightly loaded P-40 would lift off anywhere from 65-75 MPH indicated airspeed. If the carrier is traveling 15 MPH+ into a 20 MPH headwind a P40F model can do it easily. That means the aircraft only has to gain 30 to 40 MPH on the Deck roll. Easily achieved. 10 to 20degree flaps may be necessary. Remember Dolittles heavily loaded B-25 Mitchells did it off the USS Hornet. Oddly enough the only one that had a problem was the last pilot to take off, simply because he forgot to lower his flaps. The P40F Model had the Packard built Merlin engine in it and not the original Allison V 1710. I see no issues with this event in the hands of an experienced pilot.