Time for some weathering. First I used Flory’s grime wash on the entire plane.

Then a good part of it was viped off.

Next step was to use oils, in this case black, to create some streaks.

I’m no specialist at weathering, and I’m still learning, by looking at pick and other builds.
I’ll do some wear on the propeller and a few other places. Other than that I’m not sure what more to do. Other colours perhaps?