I like what I see! As for the ballance, I think the engine deck is too dark now. In the front of the hull and on the mudguards the lighter dust tones making it look like a flat dusty coat on the green metal. And this is a nice contrast. But the engine deck look's like a brown painted something. I think here you can achieve a nice contrast as well, with adding mode dry, light colors, and making some fuel stain effects.
Good work so far! Keep going!