The cantilevered arm 18 is then fastened to a top surface of thebracket 30 support arm, see FIG. 1, by a knurled screw 19; thumbscrew, fastener, clamp or other equivalent means for attaching the cantilever arm 18 to the bracket.The tap configuration illustrated in FIG. 2 and cooperating threads in the alignment bore 17 of the cantilever arm 18 are illustrative of one embodiment of a cantilever arm