Me too ... but my evil JMN doppelgänger can't help but wonder how the drivetrain is arranged
That thought had passed my mind as well. My understanding of the Kugelblitz turret was that it was essentially a ball, which means there isn't much room under it for the engine, where its situated. The grill on the side is from a mid-engined SP gun, such as a Hummel or a Hornisse but the hatches on the roof sort of preclude the engine being there. Speaking of those extra hatches, what are they there for? You have the driver and co-driver in the hull front and they have their own hatches already in their section of the hull roof. You have the commander and two loaders IIRC in the turret. So who are the extra hatches for?
Apart from that, its a nice looking vehicle. The Ostketten track is well done particularly and "hangs" well. The addition of the IR scope for the driver is also nicely represented.