I am just rushing out but my page gives you the list of US military Chevies:
http://clubs.hemmings.com/clubsites/...tarychevs.html
The BFR engine code indicates a 1942-built Flint-built rhd 215 as fitted to a 1 1/2 tonner.
Somewhere I have a list of al Chevrolet WM contracts that will tell me how it was ordered.