Great work Keith!
Your comment about the motor, I agree. I used to build 1:35 Tamiya stuff in the 80'as and remember their PzKpfw II had the same cutouts. There may even have been a comment that it was designed as such, but no motor was supplied if I remember right.
Is this a proper unofficial build? Would Airfield ground vehicles, and light tow vehicles (Kettenkraftrad, etc) count?