When done turnin you can mark the eye placement while spinning after turning. Then use the 2 square ends to find the middle of the sides and cross the lines u just made while spinnin.
I usually just epoxy the wire under the lip.Hope it helps.
i put the eye line on while spinning like others said .. Then I have a piece of 3/8 dowel sticking out of a board about 1/2"....put 3/8 belly hole of plug over dowel so plug is sitting there in place, not rocking and rolling .. Now just find a piece of material 1/4" 3/8" 1/2" 3/4" whatever puts the eye where you want it, and hold it along side of plug and mark both sides .... height of eyes will be the same on both sides and same on everyplug if same method is used ..