Search:

166134One other that I find helpfull, (Esp with Ivory) Duct tape or two layers of masking tape with a hole punched into it.
Will help with any slipping issues getting the pin out,also gives a sort...

The smallest bit you have,I go much smaller the 1/16,trust your eye, the eye always centers.

With Ivory scales,I do the entire process by hand with a pin vise,Takes alot longer but you have great control.