Ah OK Bob, that now makes perfect sense. Presumably the areas that are more exposed would fade quicker, or were they painted in different shades?
Nice mottling!
The curved fairings above and below the wing form a tight seal against the wing. The dark grey paint is in the area where the two surfaces rub together during wing sweep movement.
The slots in the fuselage aft of the wing contain inflatable bags that seal the hole in the fuselage that the wings move in and out of when they are swept back or forwards.
I started building this one and got fed up with it. Had trouble working out how the flaps fit in the deployed position. I will be interested to see how you do it. Then I will go back to mine!.
Started on the top coats tonight, I'm not sure yet if I'm going to add another one or two. I actually ran out of paint so I'll have to head to Hobbycraft this weekend either way.
Having slept on it I have decied not to add another layer. I figure that the subsequent washes and weathering should tie it together, and any additional layers of top coat will probably obliterate the mottling.
I've now maskedup and sprayed the wheel wells, air brake interiors, heat shielding, buckets and jet nozzles, and finished up the tail planes. Still got to paint the undercarriage, ordnance and fuel tanks.