Located and drilled 3/16" hole for bolt that secures the threaded plug into the top section of the clutch slider. Hole is 3/16 from the edge of the plug and clears the end of the threaded in clevis by about 1/16".
Marked clutch arm 1/2" from the end for the first hole of two that secure the arm to the pivot plates. Found center on the tube in the mill vise at .501" then used a number 6 drill that just fit through the factory threaded holes in the end of the clutch arm to align the rotation of the arm in the vise so the two holes I needed to drill would be aligned with the factory holes and eventually the screw actuator.
Drilled the first hole 1/2" on center from the end then used one of the pivot plates as a guide to locate the second hole 2" further up the tube. These were center drilled then drilled with a 3/16" bit and finally a D (.246') bit which gives a nice snug fit on the AN4 bolts.