Not all '36 low cabs have the same arrangement when it cones to interior panels, Some are like the '37 cab, as Kent describes. Mine has the headliner coming all the way down the back to the top of the window. On the front, it also curves down to the top of the windshield to a narrow trim piece which secures it in place. There is a cutout for the wiper motor and a metal cover, for the cutout, which just slips behind the narrow trim piece.
Mike