A threaded fastener, finger, pin, nail, dowel, staple, screw, bolt, or other element can be inserted into the holes 13 of the socket 12 and the aligned holes 42 (shown in FIG. 14) of the upright 40 after the upright 40 has been inserted into the larger aperture 15 (shown in FIG. 7) of the socket 12 in order to remo