If a crescent head is added to a flat top than it already has the 2x3 perimeter to add the holes (top photo).
Find the center of the 2x3 and mark that location. Continue by measuring 4 1/2" to either side of the center mark and mark those locations. This will give you the 8 1/2" width for the headpiece holes.
Next measure up 3/4" from bottom of the 2x3 and mark at the locations where the 2 holes are to be drilled. Using a 13/16" paddle bit, drill out marked holes at the 4 1/2" mark crossing the 3/4" mark.
Test headpiece rods by sliding them and determine if it glides smoothly and holes are even. Install hole brakes enclosed.
A lift back or similar cushion needs a 2x3 block added which include the two holes for the crescent head. This version also costs more because the wood block needs to be made and covered with vinyl that matches the table.
