Abstract: An adjustable mounting assembly includes a supporting member having a load bearing surface and an anchoring element extending outwardly from said surface, a variably positioned member having an opening and a plurality of threaded passages, the opening having an axis and a size for fitting over the anchoring element, the threaded passages being spaced equidistantly from the axis, and the variably positioned member being supported by the load bearing surface, a mounting plate having an aperture and a plurality of bores, the bores defining a common geometric center, the aperture being eccentrically offset from the geometric center and having a size for fitting closely over the anchoring element, the mounting plate being rotatable about the anchoring element for aligning the bores with the threaded passages, and a plurality of retaining elements for insertion through the bores, screw threading into the threaded passages, clamping the mounting plate to the variably positioned member, and positively aligning the va