Worked on the Lt side 'turtledeck' skin to Rollbar attach mod, and then did about half of the screws for the rear window to rollbar. After securing the skin with sufficient clecoes, match-drilled the screw holes in the aft perimeter of the rollbar for #6 screws (17 of 40 holes done.)
Carefully drilled alternate holes (every 5th hole) and then the middle hole between, then hand tapped the hole for #6. Also, had to manually use the countersink (deburring bit) on a long extension for control, to improve the plexiglas countersunk holes. Slight changes in the countersunk shape to improve seating the screw evenly.
Tedious and delicate but with 80 deg F temps in Feb (AZ winter), the plexiglas was safe to work.
