Here are a couple of photos to illustrate my painting technique. The plane is slightly newer and faster than anything WNW will ever do

, but the technique is the same.
The gray base coat was airbrushed with Tamiya acrylics, and the green camo pattern was drawn on with a pencil, then hand brushed. The first coat has poor coverage, but there's no buildup or 3-dimensional brush strokes.

After three coats, the color is even, and there's still no buildup.

If there is any buildup, sanding with very fine sandpaper, say 12,000 grit or so, will take off the high spots. If too much is removed, its easy to touch it up.
Since I use acrylics almost exclusively (the only exception being spray cans of Tamiya lacquer primer), I'm going to experiment with artist's acrylics to do the wooden cockpit floor of my Eindecker. There are various retarders available to make acrylics dry slowly, which will hopefully mimic the way oils behave.
Peter