I would copy and paste the material zones from each section into your VSS Templates after you've gotten each MAT zone created and labeled.  Delete the images for each Image_map node, those will not be needed by VSS.  For those Image nodes connected to a math_function node, temporarily disconnect from those nodes and connect directly to the PoserSurface plugs occupied by MF nodes.  Do this one zone at a time to avoid confusion later.  Run the Python Script Rename nodes from the VSS Script panel, then reconnect everything the way it was originally.  You need to rename those VSS nodes correctly for VSS to work.