Okay, to be a contrarian...
I think the weathering you have looks good, it is really easy to overdo it. Look at a taken photo at the same distance the plane appears to be in your jpg and try to match that. You see a bunch of stuff up close that you cannot see at a distance.
Look at the picture you posted of Dikam Death. The CBI is a fairly primitive Theater. There is oil visible but not much chipping on the cowl. The paint on the leading edge looks fairly beat up, but the fuselage side is not bad at all. I'd bet the walkway is badly worn, but the outer wings should be pretty clean.
You tend to see chipping on American airplanes in places where people move around, or on the edges of panels that are removable. You generally see no chipping at all on outer panels or National Markings.
The forward edges of the wings and tail will chip and weather over time, particularly if there is rain common. Rain, strangely enough, will strip the paint right off a high-speed airplane, but only the leading edges. I'd suspect that repainting in the field was common in WWII. Note the 'patchy' appearance of many airplanes.
This is all a long-winded way of saying 'less is more'.
