I painted it grey, and used silver paint pen to add color back, and a little black wash for the shadow effect. did dullcoat after assembly,which gave the windows that dirty frosted look, and brushed alcohol over areas that need a chalky/ dusty look {see stairs/post under loader}- same color as door
I have later found that Sharpie makes brown pens, that work great over the silver/grey for rust stains.
sorry don't have better pic, just happened to be in backgroud.
brown sharpie used on coaling tower
click on pic for full size.