This is an interesting photo, taken near Alaska,
Of course, you can see that there are two B-24's, presumably D models and obviously equipped with radar.
The fighters are all P-40's and what is intriguing is the mixture of types. The short tailed P-40's must be E models, because they have not the fin filet of the K nor the longer tails of the later F's, L's and M. Since they have carb air intakes on the upper cowl they are not F's.
There are also P-40N's in the photo, as is shown by the expanded clear canopy section aft of the cockpit. The first N's came out in March 1944 but the N-5 with the larger clear canopy did not come out until later than that.
One of the short tailed P-40's has Aleutian Tiger markings used by the 11th Pursuit Squadron, which started flying missions in AK in the middle of 1942. The P-40K came out in August 1942, so there were no more E's built after that
So it appears they were still flying some P-40E's in AK around 2 years after they came off the production line. Given not only the rigors of combat but that of the AK weather I think that is impressive.
Edwards Park, the P-39/P-47 pilot, said a friend of his who flew P-40's in New Guinea stopped by to visit him and complained, "I don't know when we will get any new airplanes. It looks like we can't wear out these P-40's."