Pass 1 divides the half-width and thickness in half. Pass 2 uses a quarter of the thickness and one-third of the original first facet. Pass 3 uses one-eighth of the width and the midpoint of the original first facet.

The dashed C curve is an elliptical fairing guide. It does not alter your marks or define a historical neck profile. Check the truss-rod channel, hardware clearance and remaining wood against your actual blank before carving; use calipers and a physical template for final shaping.

Print at 100% / Actual size and measure the calibration square before using the templates.