Hanno, there were 3 designs, with the latest having a near vertical (short) steering column. The driver sat between the chassis rails (the floor fixed to the underside of the chassis???) and the master cylinders being above the hanging clutch and brake pedals. (hydraulic throttle as well)Low silhouette was "in", in 1943. The C291QH was 42-43 101 1/4wb.(third design) (modified FAT Chassis) Only two fuel tanks.
The 1941 C19QHF was134 1/4wb. Modified from CO1QF 3 ton Chassis. This had 4 full sized fuel tanks.
The 2nd design (1941-42) C191QRF was also 101 1/4 wb. 2 tanks.
1st design had 16" wheels the 2nd and 3rd designs had 20" wheels.
"H" is for Hanno!!!
I hope that helps a little.