Maybe not real helpful, but I Googled, 1928 Model A Ford Pickup, then clicked on images and I come across a few black and white photos of a 1928 closed cab.
Here are a couple. You can blow them up to the size you need and trace them (ala Foose or Kendig) to make a few copies to test colors - or heaven forbid how it would look with the top chopped a nice rake and no bumpers