Lower sheet metal outside piece three 9/16 holes 7/8in. to the center of the holes. One in the center and one each 4in down from top and 4in up from bottom. On inside welded to the lip three plates 1in by 1 1/2in with a 1/4 in 20 tpi tapped hole 1/2
in and centered. Otherwise the hole would be 1in from the other side of the plate. the plate is 1/4in thick. It is welded so that the center of the hole clears the panel by 1/4in. and match the oppisite panel. Hope you can understand this and it helps. Mitch