if you can set up a default basemesh for the retopo of all, you could also have a look at UVLayout for a 'base' UV-set: http://www.headus.com.au/doc/uvlayout-expert/videos/UVLayout-Reshaping.mov (prolly take the most extreme 2 of all the heads and set up a 50/50 base UV-set to be used for all the heads...trade-off, of…
howdy Droma. My point was to make the retopo head first (the default base head geo you'll use for all the heads), snap that retopo to 2 of the opposite-but-extreme versions of heads you need to redo (so you have the extremes of where your retopo geo will need to be---but those 2 resultant retopo heads have the same vert…