Making string grooves in limb tip

[quail]

I am looking for ideas for a jig to help align the nocks/grooves in the limb tip. I would like repeatable accuracy to keep grooves teh same depth and in perfect alignment with each other. If I can come up with the best idea I am probably headed to a machine shop.

[Trux Turning]

This is how I do mine.. not much of a jig but the second one always matches up with the first one. I mark and cut in the first grove- then flip the bow and put something (allen wrench, round file, etc.) into that grove and just sight down on that as I cut the other side.
 

[PEARL DRUMS]

I do the same thing except I use the rat tail file I used to rasp in the first groove.