below is a drawing of all the pieces giving the dimensions for the hole positions.
Also are drawings showing the wire threading layout.
Refer to the cutting list on the previous page for the lengths of the individual pieces.
Make all the holes ¼" (6mm) diameter and drill through the wider face of the wood.
In other words, the wood size is 1½" x 1¼" (45mm x 33mm), therefore drill through the 1½" (45mm) wide face.