Thats an interesting pic !. I've attached a pic I took at Flying Legends back in 2007 of a P40 with an Aleutian colour scheme for comparison that raises a few questions from me that may not all be attributable to differences in the marks....
Interesting to note on the old picture....
Is that a complete 'leather ?' shroud over the exhaust stubs (looks like a small grab string at each end to pull out the stub 'caps ?.
Lack of 'cooling ?' panel immediately behind the prop spinner (on the modern pic, the panel has 5 x rows of 3 holes).
No external gunsight ring and bead on the old pic.
Routing of brake pipes compared to the modern pic
What is the 'hole' in the wing root (gun camera ?) that is not on the modern pic (unless its at the front of the undercarriage leg fairing ?)
Extruding gun barrels on the modern pic...Was this due to different guns originaly installed or just to make it look good for airshow fans
Slight variations on the Tigers head.
No apparent undercarriage down 'warning 'rod' showing on top of the wing (painted yellow in the modern pic.)
Is that a hole for firing flares through (about midway between the front of the main windshield side screen and the wing) thats not on the modern pic