Bodge, the DS T48 w/EEC tracks would really help this one, or if they're easier to come by, Academy also supplies them in its M4A2 PTO kit. TWS does a trans cover that works nicely also...
Personally, I would be careful on the weathering, since these tanks were realtively late arrivals in the ETO and wouldn't show a lot of chipping, if any, since the whitewash was water-based, but that's just my take on it. Maybe rubbed off instead of chipped....however I'm very interested in what you come up with. Model on, Garth!