Abstract: Golf putting structures and methods for dual-length conversion of a putter-club, including height adjustment to facilitate a pendulum-like putting stroke so as to minimize the opportunity for outside interferences. Adjustable length and rapid conversion features provide the option of using a first preselected putter length while enabling ready conversion, without attracting undue attention, to an extended length. In one embodiment, a hollow tapered-shaft putter is readily converted for receiving a coupling means of preselected configuration conforming to that of the hollow shaft which is integral with an externally-threaded adjustor rod. The remaining distal end of the adjustor rod is threaded into a receptor bushing which is integral with a height-augmenting receptor structure. Threading the rod into the receptor structure can be used to adjust the overall height for the combination structure.