Good to know. 
Here is where I am at today and my current plan.
Added some vegetation and more mud/grass to address some spots.
Letting that dry before I add Vallejo Splash Mud, pigments, thinned buff coat and steel color top of track, then a light new rust color in spots.
Glossed the gun in preparation for some brown panel liner, true metal old bronze on the emblem above the door, dull coat then a thinned buff sprayed along the bottom.