Thad, Aurora, joe, thank you for your comments. Very much appreciated. As for the paints, I started off with Gunze Mr. Base White for the white. Then I used Floquil Intermediate Blue cut with about 15% FS36622. For the Dark Sea Blue I used Testor's MM FS15042 Dark Sea Blue cut with FS36320 and a little bit of FS36622 as a base. On top of this I added more FS36622 and resprayed the top of the wing, the cowling and the spine to get that sun-baked look. I didn't aim for complete coverage but more of a blotchy look.
To Jabbe, your "cheap" AB is perfect for the job. Just freehand the camo and afterwards use a brush dipped in thinner to clean up the edges. Just get the bristles wet, not soaked, and drag it along the edge of the pattern to clean up the spatter. How close you get to the edge of the pattern will determine how tight your camo is. Other than this, you can cut masks and apply them loosely to the model, ie, raised above the surface of the model.