In the future this space will go into great detail of the differences. It will also go into detail of when slight changes in the "straight" M151 (not A2 or A2) during its production run. There are quite a few things that changed in the early vehicles that will be very hard to detail as to when they changed. So if this feels unfinished.... You're right, it is.
The M151 had possibly 3 different body manufactures, and 3 complete vehicle manufacturers (Ford, Willys Motors, & Kaiser Jeep Corp.)
Undercoat applied at factory
There are a few items that are M151 only (not found on the M151A1), and the vehicle having them or not having them will tell you what is correct or what you are looking at.
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