Guitar Headstock

FIG. 1 is a front perspective view of a design for a guitar headstock showing my new design; FIG. 2 is another front perspective view thereof; FIG. 3 is a front view thereof; FIG. 4 is a back view thereof; FIG. 5 is a left side view thereof; FIG. 6 is a right side view thereof; FIG. 7 is a top view thereof; and, FIG. 8 is a bottom view thereof. The elements shown in broken lines are for illustrative purposes only and form no part of the claimed design.