Just finished painting & mounting these guys. Picked them up at Chiller. Each skull is a little larger than 1/4 scale (Sideshow Premium Format scale) noggins. Bases were made from aquarium rocks:
(http://i175.photobucket.com/albums/w121/pbregman/Gillman1.jpg)
(http://i175.photobucket.com/albums/w121/pbregman/Gillman2.jpg)
(http://i175.photobucket.com/albums/w121/pbregman/GIllmen2.jpg)
(http://i175.photobucket.com/albums/w121/pbregman/Gillmen1.jpg)
http://www.neckboltpublishing.com