Ah, if I might add about two cents...
1cent:
..the panel lines seem to be very defined, but personally, I don't think its awkward or anything. It does add to the features of the plane. Some people just choose to make panel lines light and undefined, while others go deep and very defined - its just a matter of preference and which makes the plane look best. But if I might add a little suggestion to it,
IF the skinner chooses to portray the panel lines deep and distinguishedly, then a secondary highlighting/shading could be applied to the appropriate surfaces to make it more natural.
Its kinda difficult to explain since the Pic Hangar went loco and I can't post an example - but look at the second picture, the port side wing from the cockpit. The lines depicting the leading edge slats, ailerons, flaps, radiator flaps are very well portrayed. However, on a broader perspective, the separate parts of the wing still look like it is made from a single piece of wing-shaped metal - which is not the case. What I mean by this, is that the slats, flaps, ailerons, flaps and etc etc.. are all moving parts assembled together. These parts leave an amount of space between each other to allow movement, and where there is space, there is always corresponding shadows and highlights that follow along the ridges of that space.
It is but a small bit of detail, but when added, might do a lot of good.
2cents:
The underbelly is the dirtiest part of the entire plane. I may be wrong, but IIRC the conditions of the Eastern Front/Continuation War Front airfields were also often very crude. When a plane rolls on a dirt field, the tires always kick back dust and grime, and these marks hit the underbelly of the plane, and it stays there for the whole flight. The tires also kick back small pebbles and such, and these tend to hit the underbelly of the plane, leaving their marks. Also, any kind of leaks - maybe leaky joints, lubrication oil, or whatever that's inside a plane that might leak a bit - will almost always seep through the belly of the plane, and flow back along the air-wind direction. I remember a picture of a Spitfire Karnak once posted, and man, the belly was really dirty. Perhaps someone could ask Karnak if he still has the pic, but it'd give one general idea on what a belly of the typical WW2 plane might look like.
