Does it say Oliver on the side or does it say Oliver Superior?
The measurements you give are close to a model 7AW, or most likely a model 17.
The spreaders that were green and built in 1954 and earlier had a red hitch and red wheels.
The spreaders that were built in 1955 to 1958 were all green.
The spreaders built 1959 and later were green with white wheels.The above dates are approx.,but close.
Don't complain about "some goofy jack set up" until you have tried it. If its all there including the hitch pin with a rod sticking straight up, it is the slickest way to hook up any spreader I know of.. You hook up with out getting off the tractor.
To each his own I guess.