Originally posted by Joe B
If you take an exacto knife or even a sharp body reamer and just make a small indentation in the center of the brush , Just enough for the drill bit not to skate around , you shouldn't have any problems in getting it nearly perfect......Iv'e done many pairs of brushes this way with good results......the most common size hole to make, is a number 42 bit = (3/32).......drill in about 3/32 deep also.............. 
Thanks alot I have been searching for a while now trying to figure out what size a #42 bit was.Basically your saying I dont need a jig ,am I correct?