The chalkmarks on the turret look really good! That's something I still haven't tried- the primer with the construction marks still on it. It's a neat look and I'm looking forward to seeing where you take it.
I've heard about Soviet tanks being driven right out of the factory to the front line in the Battle of Moscow but never seen any photos of them. Not sure if it's just an urban legend or not. That's something I'd thought about trying to do.