ID needed for US vehicle and unit in Holland, 1945

[motto]

They look to me to be 20" wheels. The bumper is also the heavy truck type as used on military/government contract vehicles.
The cab has a join above the windscreen which to me means that the manufacturer supplied the vehicle with front end sheet metal finishing at that point. The body work aft of the join would have quite possibly been built 'in theatre'.
What appears to be 'a heavy piece of chrome bar going across the top of the grill' is simply light reflection off wet body work. The front end is standard for the 1-1/2 ton truck.

David