I am soon going to replace the headlining on my Ranchero after fitting 3-point seatbelts. It is a 66 Deluxe . There are holes either side of centre , 21 inches apart , above the rear window. Something has been screwed on there in the past and I am wondering what. Maybe coat hooks ? I am sure one of you knowledgeable folk out there will know what should be there. Denis.