There was a Zygote Muscle Man and also a Beast Master I think... might have been used for the centaur... might use the Poser 4 Casual Man head or something. Anthony Appleyard has a little app that fixes the vertice order or something on the P4 Casual Man and maybe Busines Man so it/they can take standard Dork head morphs. I think those are the P3 Nude Man head on those old figures like the Dork Merman. You could also try hybriding on the P4 Nude Man head since the neck seam should match up maybe. You could use the old P4 head magnets to do some work and I have actually had some success using the application Morphing Clothes to move morphs between different mesh with the same basic shape and grouping, even expressions.