The rocket mounted was a limited run of L models with mounting points for that rocket type, about 250. The wing bomb racks from what I could research are field mods. Notice the drop tank, I think the white rear end on his wingman was used in the Pacific. The 4 hood guns are the first run of 20 P-39C which were converted to D models with the 30 cals removed from the nose and mounted in the wings.
P-39C Model 13 Production model with one 1,150 hp Allison V-1710-35 engine, with one 37 mm cannon firing through the propeller hub, and two .030 Mg and two 0.50 Mg mounted in the nose.
As the first 80 production models of the P-39C started arriving at USAAC squadrons in January 1941, the first 20 were configured with two 0.50 caliber and two additional 0.30 caliber machine guns in the nose. The remaining 60 were provisioned with two extra 0.30 caliber machine guns, self-sealing tanks, and a provision for a 500 lb. pound bomb or 75 gallon drop tank carried beneath the fuselage. All four 0.30 caliber machine guns were placed in the wings and this was designated as the P-39D.
Two ordinance options, one a field mod, that will make the P39 need it's own fighter cover. And a short term variant that existed for a run of 20 aircraft almost a year before AAF P39's fired any angry shots at anyone.