Sorry Bruce. My laptop died and I'm waiting until payday to build a new desktop so I'm stuck with my phone for now and posting from this thing is not as easy. Anyway, to answer your question, I do have plenty of washes and might use a thin grimy black. Should darken up the model overall and pick out the details. Whe n I start rusting and adding dirt buildup, where should I concentrate? Never weathered a tank and my picture search isn't giving me any good and dirty pics to use as references.