now that i'm not on my phone, it looks like this has drawing and some dimentions you actually asked for
http://www.steelsoldiers.com/upload/M35/m35a2_camo.pdf
more dimentions here
http://www.steelsoldiers.com/upload/...0-209-10-1.pdf page 48
sorry if I was a bit overkill on you, this truck I know where to learn about. I'm not sure where to start looking for the Opel 3T, and my german is rusty highschool level.