[Sledgehammer427]

well, one problem I've found in the Steel Fury series and adding a stock cockpit or stock what have you into a new tank is that they are all kinda connected. the interior is connected with the exterior in game so that you get the feeling of popping out the hatch, and then jumping back in, the ventilation flaps on the Panzer IV's turret (so far the only tank that has been replicated with a stock cockpit)
because the interior has openings, the modder will have to precisely fit the openings with the openings on the exterior model. lots of trial and error and much easier to just leave the cockpit out of the equation and give the player the bare essentials until somebody with a lot of spare time can make a cockpit for every tank added in the game