Oooooops, let's try again :-)
Andy, That looks really good (sounding surprised or really suprised if Nige had built it )
The white over painting looks good, maybe just a tad of weathering back to the underlying colour, at some of the edges, if you wanted a more weathered look. It accurately reflects the picture you supplied though Certainly the weathering around the lower half looks pretty good too and I don't think that you have over done the road wheels.
Remembering that I used to "own" my own tracked vehicle:
The track, where the road wheels contact it, and if it's steel, would be polished steel. This is true even if the tracks are caked in mud, as the contact of the rubber on the wheels, with the track surface, keeps it that way. If the vehicle then stands still for a couple of hours these contact points gain a surface rust layer. This surface rust disapears as soon as the vehicle moves again. The sprocket wheel teeth are also in constant contact with the track, so they are warn as are the track guide slots. The sprocket teeth show this ware at their edges and tips. The track guide teeth rub on the inside of the road wheels and show a similer polished metal look, usually to about half way down. If you dicide, in the future, to simulate this ware, don't use bright silver paint, as that would look wrong, on a model.
The antenna on AFV's are, usually, made from brass sectioned tube and therefor are straight. On the picture that you supplied they have be pulled over, by a cord (supplied as part of the radio fit), to keep them out of the way of over head cables. They are pulled down so that they still clear the turret and don't get in the commanders way. You can see this cord on your pic, look at the commanders helmet. Although the antenna are rigid the base is designed to allow flexability (i.e. It's rubber). When the antenna is pulled over like this it does curve a little. The two antenna would be over in a "X" shape but not touching. If you can see the cord you will see where it's fixed at an angle to clear the rear turret. Having said all that, the vehicle thayou have depicted is different than the pic. The main gun is much longer and will interfere with the antenna anyway, which might have something to do with why they appear shorter (fancy camo pic), if they were tied down the cord would be simply push off, if the main gun were to be traversed over the rear.
So what I'm saying is, the antenna should be straight
Mal