Based on the 3d model by Distefan, which they describe as a "Ward Diamond T". It was actually made by Ward LaFrance and Kenworth.
I replaced the wheels and radiator brush guard, added the tool racks, oxygen bottles, black out lights etc. Re-UVmapped and textured too. The cabin had to be completely rebuilt too.
This is made as the late model 1000 series 5. The Kenworth version of the M1A1 had a different radiator brush guard.