That title was a mouthful. I magnetised this one as seen here.
Test scheme WIP:
Undercoat: Vallejo Mecha Black
Blue: Cobalt Blue blended up to Primary Blue by hand, highlights Primary Blue then a mix of Primary Blue and Art White
Pigments: Dark Mud mixed with Rough, then Dark Mud, with Mars in the recesses, then Natural Soil on top
White: Artic Blue then Art White
I think the pigments ended up reading more red than I expected; going to back that off a bit to try and make it look more like dust accumulation than rust.