I took a little scrap of sheet plastic to use as a straight edge and used a combination of a lead drafting pencil and Prismacolor colored pencils in black, light gray, and yellow, to get an effect that looked something like the real one pictured in the book. After drawing the scratches, I blended them a bit with a small eraser, dusted the whole door with bit of medium gray pastel dust, and sealed it all with a light coat of Dull Coat clear flat.
I'm quite happy with how it turned out.


I also added some light fluid streaks in areas that the book showed get some staining but they are hard to see in these photos. I used Tamiya Smoke diluted with Tamiya Clear. I'd place a tiny dot of the paint where I wanted the streak to start then wiped it back with a bit of soft foam. I wanted just a hint of the staining as the real planes are kept clean and when you scale it down, it should be barely visible.


Cheers,
Eric