Joint Refitter is here. In the hope it will be useful, but without any warranty. Absolutely no warranty.

cgscripts.colorcurvature.com/CO_RefitJointCenters_2012.pyc

One note regarding the M4-V4-K4 thing: K4 has rotated polygons and if you export it with my exporter and try to use this as the morphed object for M4 or V4, this will not work, because for my exporter the vertex order depends on the polygons, and K4 is different from M4 and V4. As a workaround, you can use poser's export, with options WELDED and INCUDE BODY PART NAMES, and all other options off. PML should accept .OBJs created this way also.

 edit: It requires PML 2012, and must be placed in the same directory as the other CO_... scripts.