Yeah, the kit in the Revell boxing originated with Monogram. It remained in the combined catalog after Monogram and Revell were merged, right up to the Hobbico bankruptcy and the end of Revell-Monogram.
Revell only ever kitted the P-40E, first in 1/32, like the one Down Time showed, and then they pantographed it down to 1/48 scale.
After the merger with Monogram, Revell's P-48 was the basis for the ProModeler P-40E. Along with refining some details, RM added a couple of figures from the large bomber kits. They added the ground crewman, standing pointing up, and the pilot in overseas cap, modified to have one foot resting on a little box.
Airfix' kit is nice, but I didn't make me get rid of the remaining Monogram P-40s in my stash. It still builds into a nice representation of a P-40B.