What's the number on the engine block? (drivers side mid-way down the block just under the cylinder head and right above the water inlet.) If no number there you may have to lift the body to get at the number.
Or you might check the paperwork that came with it as it may list a VID which more than likely is this number.
AR is certainly early - but one has to be careful in assigning AR designation to any vehicle. Trucks especially. AR did not all happen at once. Also Ford made up trucks basically from the parts that were outmoded for various reasons on the regular automobile line. Or rejects on quality or appearance. My March 29 CC pickup embodies features normally found on cars 3 months to 6 months earlier (Like powerhouse generator, fluted headlights, 4 finger headlight switch, drum taillight.) And the gearshift lever had been painted, I think factory, to cover up imperfections in the chrome.
Check around and get back to us on this can you? It may be a VERY interesting truck given it's source and the station in life it's first owners occupied.
I kind of like the early features - they harken back to a time when automobiles were somehow "simpler." But Ford did make improvements as he went along. Some for legitimate reasons of successful driving - some to improve quality - some to lower costs.
Joe K