[Hanno Spoelstra]

As can be seen in the Chevrolet catalogue “Flat face” means the vertical part of the cowl is flat with A-pillars being perpendicular to the chassis. This gave body builders all the freedom they needed to build bespoke cabs and bodies. So it doesn’t refer to the cowl vent area to be flat (alone).

So the buyer ordered a chassis/cowl and then contracted a body builder. Especially in Asia even today truck builders still make chassis/cowls, for outside contractors to build a body.