The oil door on the top right rear of the cowl had been carefully fitted by Zach Chase. He attached ribs to the underside to force the door to curve to fit the curvature of the cowl at that location. Stratford in these photos rivets the door hinge to the cowl and then the hinge to the door using a rivet squeezer. After drilling the holes for the #40 rivets, he used a countersink tool so the flush head rivets sank into the fiberglass.