I was active duty Army from February 1964 to August 1970, never saw an M-151 with the spare tire mounted on the side like that one. Every one I drove, whether in Germany, Viet Nam, Korea or stateside, had the fuel can on the rear above the bumper on one side and the spare was on the other side above the bumper. I spent a lot of time in a 151, my job was communications. The definition of a "Radio Truck" was an M-37 3/4 Ton with Commo equipment in the back. ALL the M151s had the same radios. It was my job to put them there and maintain them.
I would love to have one now. I remember cruising down the Autobahn doing 90 MPH in them a lot of time. I know they don't register 90 MPH but the speedometer was wrapped around waaayyyyy past 60 (about 50% past). Those little Ford engines would really hum and had a very distinctive sound while running that fast.