Although the illustration of the tricolor paint scheme is clear in the instructions, I would like to verify one aspect. I have not found a clear enough picutre anywhere thus far to answer the question.
That is, does the border line of the underside color come up to meet the wing root under the wings, or rather does it continue straight. Or maybe it was done both ways.
Here is one picture of wildcats in flight . The paint jobs are all a little different. The white runs straight across the bottom, but they have different amounts of shadow shading under the wings.
The principle of countershading would have the borderline come up to meet the wing leading and trailing edge. However, on many two-color F4Fs the dark color was continued across under the wing contrary to that principle. The few pictures I’ve seen of the tri-color scheme on the F4F, with the notable exception of the #1 posted above, seem to be properly countershaded. So it depends on the specific aircraft that the Hasegawa markings represent. Good luck with finding a picture of it, but there must be some source they used that isn’t too rare…