This looks wicked. You've got the facial details spot on. Only critique would be that the back of the head needs to be more bulbous. I had this issue when I sculpted mine. Please keep updating with pics.
Great work, love it. Wish I could master latex mask making, and so quick. Out of interest what did you use for the base of the sculpt? Been looking for a good mannequin head for a while now and yours looks pretty good.