In reponse to tips I added more debris, random burned stuff made from sawdust that I mixed with
Tamiya flat black paint, which also glued it into place. I then drybrushed it with grey again, and I also added rust to the torsion bar and ammunition boxes in the burned areas, by painting small, random spots of orange and red-brown:
I also added the radiator and its duct, with a painted muddy patch where water would have leaked (just brown paint) and some streaks down the duct below the holes the water drained from (
Tamiya Smoke).
You can just see I also put the trim vane on, as if it’s come off its right hinge but the left one and actuating arm are still attached. The text on the inside is a decal from an old
Tamiya M113 kit.