Good to know the shorter weights are available for this application. Is the original arm base for the JMW-Classic 10.5" compatible with the JMW 10 3D arm? If so, does the base have to be moved to accommodate the 3D arm or do they have the same pivot to spindle distance? I just became the second owner of a Classic 3 with JMW-Classic SS unipivot, and am curious about this upgrade path in the future.