I have been using a brass rods of different diameters. I cut a concave in the end of the rod to hold the paint and spread it a little out from the eye (bump) and then come back and paint the center with a contrasting color. This can be done with a ball burr in a drill or dremel. The trick to find brass rod larger than the eye diameter. Idea would be to use bronze brazing rod. Got my brass rod from a clock material supply house back when I did clock repair years ago.

Redman