Your White seems to be a bit thick...try thinning it down with water (Although, depending on it's age, you may just have to get another pot). If you paint the whole thing with a thinner white paint, then hit the rcessed lines in the gun and such with a black technical pen (like a Rapidograph), you mey get closer to the result you are looking for. Still, the color scheme is quite good, it just suffers from execution. The reds are especially a nice touch. I look forward to seeing more of your work as things get better!