I posted images my first model over on the HeresyBrush forum, and had some good feedback on improving on my first attempt, which suggested I reduce the size of the chipping and lessen the chipping on the main part of the tank's body.
I have tried to follow this advice on the remaining StuGs, but perhaps needed to take it further.
The second StuGs were painted as the first, and all three are now matt varnished too.
I think they are an improvement, let me know what you think.
(The first StuG is on the right, or # 412)