I know it says A2, but I THINK you have an M274A3, which is an M274 that had the AO-4-53 4-cylinder engine removed and the AO-42 2-cyllinder engine installed. I have never been able to detrermine who did the conversion work or what the contract number was, but it could have been Baifield Industries, since they went on to build the first contract A5 mules in 1965. The M274A1-to-M274A4 conversion work was done by Kaiser Jeep Corp., according to the few A4 plates that I have seen.
The engine data plate is a very early Continental plate, which would also support the idea that it is an early AO-42 engine.
If you don't mind, could you check and see if your bed has the extra muffler mounting holes on the right side and see if it has 1" spacer blocks between the frame tube mounts and the rear bed supports. Also check the engine guard and see if it has provisions for mounting the engine hand crank guide plate.
I have serial number/registration number data on over 500 mules, mostly A2, A4, and A5 models, yours may be the first A3 data plate that I have seen, thanks very much for posting, I am excited to see that data plate!
PS - just noticed another unusual thing, both your engine and machine data plates carry the same contract number: DA-11-184-AMC-39(T) and the same Ordnance Serial Number: KM000016. This gives more credit to the idea that the engine was installed and the machine re-taged at the same time during an A3 conversion.
Normally, the Ordnance Serial Number would be what was painted on the side of the mules.....at least on the A2-A5 mules..
