This is a planed  self propelled gun mounting a 170mm gun. This picture gives an impressive idea of the size of the fighting compartment on the vehicle. The gun platform could also be moved out of the vehicle with a built tray.

Gerat 809

7.5cm PaK 40/1auf Lorraine Schlepper (f) A French sourced prime mover armed with an anti-tank gun. 170 made. This one is seen knocked out with damage to the tracks, somewhere in Northern France. Picture must have been taken some time after the battle as the refugees filing past don't seem to be in a huge hurry.

SdKfz 135

Knocked-out Panzer III,Tunesia,Mareth Line,10th Panzer Div,7th panzer regiment.Note shell hole in the side.