Steve Voigt
Excellent project.
What's your fixture for planing the facets?
For planing the bed and breast angles on skew planes (rabbets/dados/fillisters), I use dedicated shooting boards. See below. I push the point of the wedge into the fence and adjust the angle freehand; I imagine the same technique would work nicely for pencils. Maybe you're already doing this, in which case, carry on!