So I have undercoated the tank (Citadel Chaos Black spray) and given it a base coat of Humbrol Dark Green spray.
I masked the tracks to reduce the amount of over painting that was required. I have painted over the black with a mix of Vallejo Hull Red and Black Grey. The spare track pieces were painted with a more mix containing more Hull red. The exhaust pipes and the front tow hooks have also been painted.
The wheels need a bit of touching up.