The ornamental design for the headstock for guitar, substantially as shown and described.
FIG. 1 is a front and right side perspective view of a headstock for a
guitar showing my new design, with a guitar shown in broken lines for
purposes of illustration only and forming no part of the claimed design;
FIG. 2 is a front elevational view of the headstock;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view thereof; and