Marion,
Re: Vehicle markings.
Memory tells me that the unit to which the vehicle was assigned appeared in stencilled white letters on the OD background, on the left side of the front and rear bumpers. For example 3-7-I (Third Division, 7th Inf Regiment).
On the right side of the bumper appeared the Company to which it belonged and the sequential vehicle number assigned by that unit. (B-4). (Company B, #4 vehicle)
If I remember correctly, the eight or more digit number stencilled on the side of the hood, was the vehicle serial number number.
Also, the driver's name was usually stencilled on the driver's side just behind to entrance. (Ex. PFC Norman Steele). Each driver had his own vehicle and was responsible for its maintenance and replacement of fluids. The work might be done by Motor Pool personnel, but the driver was responsible to see to it that it was done as scheduled.
Russ Cloer