If my opinion counts, the
ochre areas are ALG-1. I actually have no doubts about this!
It's the same brown-ochre ALG-1 that is shown at Albom Nakrasok ALG-1 chip.
No mysteries there, the chip is darker because it's fresh, Il-2 wing is lighter because it's weathered (better to say sun bleached).
Same ochre ALG-1 is used on Musee del'Air Yak-3 on engine cowlings and other large dur-alluminum panels.
Same ochre ALG-1 was used on postwar Li-2s.
Same ochre is visible under green camouflage paint beetwen two guys
Conclusion: ochre was very common ALG-1 colour.
Regarding this Il-2 wing:
I have seen many pieces of wrecks were exterior (camouflage) paint is 90% washed away and what is left is underlaying primer. Zinc-chromate is more resistant to weathering than camouflage paints, especially nitro paints. Zinc-chromatte etches alluminum surface and forms compound with alluminum - zinc chromate will not peel off the surface like nitro paint.
It is posible that the gray areas close to the trailing edge are actually remnats of the camouflage paint,either AMT-1 or AMT-12. Impossible to determine which one because the paint is degraded.
Regarding EP:
In 2008 in his Albom Nakrasok tirade, Pilawskii finally identified this as ALG-1. Before that, around 2005, he made following Il-2 profile:
under the influence of the same photo
HTH,
KL