The ornamental design for a hosel and head of a golf putter, as shown and described.
FIG. 1 is a perspective view of the hosel and head of a golf putter showing my new design; the portion representing the lower end of the shaft is shown in broken line does not form a part of the design.
FIG. 2 is a right side elevational view thereof.
FIG. 3 is a front elevational view thereof.
FIG. 4 is a left side elevational view thereof.
FIG. 5 is a rear elevational view thereof.
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof, showing the sole of the putter.