i am wanting to replace my headliner soon and i'm trying to see what i need. i look up in the cab and there is bare metal with screw holes. what do i need. i think my headliner is one piece because there are no holes to indicate a center bracket unless it clipped on. are there barackets on the front and back? or does it just screw to the cab with screws and decorative washers. 1951 6400