I made (and attached) a 1:1 drawing to simplify drilling the additional AN hole in the fuel cell cover. Print it out, punch a divot in the center of the new hole on the drawing, place your cover on top of the drawing, tape it in place, flip it over, and use a transfer punch. Can't really mess it up.
As an FYI, the drawing provided by Honda did not quite match the cover on my 84. The existing AN ports were in slightly different locations. I fixed those up but left the position they specified for the new hole. This way, the drawing will line up with our fuel cover and nobody should freak out.
Oh, and the callouts are in ANSI since the metric system is the tool of the devil.