Pay very close attention to what you watch on the History Channel and you will find that, often, their accuracy is.........suspect.
Quick example...show on the AVG...said their P40b's were armed with 20mm.
I believe the C or D did have a mount for the 20mm's in the wings although never poroduced at the factory, it may be possible to have a few field modded? The mount was removed in the E model.
"The radiator was increased in size and moved forward, 175 pounds of armour was added, the fuselage guns were deleted, and two 0.50 inch machine guns with new hydraulic chargers were installed in each wing. There were additional provisions in the wings for two 20 mm cannon, but these were never actually used"
" An order dated February 18, 1941 increased the armament to six guns in the wings, and subsequent aircraft equipped with this armament were designated P-40E (Model 87-B2). The cannon mounts (which were never used in any case) were deleted."
?
H81: P-40/P-40A
H81B: P-40B and P-40C
H81A-1: Tomahawk I, Tomahawk IA, Tomahawk IB
H81A-2: Tomahawk IIA and Tomahawk IIB
H81A-3: AVG Tomahawks
"During 1941, 100 RAF Tomahawk IIBs were released and diverted to China and served with the American Volunteer Group (AVG), the famous "Flying Tigers". Curtiss company records list them as Model H81-A3. The Tomahawk IIB was more or less equivalent to the P-40C, but some sources list the Flying Tiger Tomahawks as being equivalent to the P-40B. As previously mentioned, there are some discrepancies between Curtiss records matching Tomahawk designations to RAF serials and to equivalent US Army P-40 models, so there is confusion on this point. Erik Shilling, who was a member of the AVG and who was also a flight leader and an engineering officer for the group, maintains that the aircraft with the AVG were actually export models of the P-40B and not the C (after all, he was there and he ought to know). He says that the aircraft did not have the equipment to carry the external 52 gallon drop tank, nor were they equipped with bomb shackles. In addition all of the fuel tanks had external self-sealing material, not internally mounted sealing material as in the "C" model. Also the Model "C" had armour plate in the front, ahead of the pilot, installed on the firewall between the two 50 calibre's, the AVG's planes did not."