Hi T, can you post a pic of those eyes???
If they are domed with a flat back and you want to countersink them in the plug you will need to use a "brad bit " for your drill the same diameter as the eyes. Then what I do is drill a hole where I want the eye to be deep enough so that the edges of the eye are in the plug. I use a small dab of GOOP to glue the eye in place. It's a snug fit if you match the bit size to the diameter of the eye and looks professional.
Hope this helps.
Good pluggin,
Bernzy
P.S. Where are you from in W. Mass?, I grew up in Holyoke