Wow the modeling is fantastic and the texturing is even more outstanding!!
I was watching the Two Towers Extended edition dvd's special features and there is a feature on how they created Gollum. I think they used the same idea as you, and used layered texturing to create his skin. (Have you thought abuot being a texture artist...I have noticed CG humans are becoming popular in movies, as well as other photoreal creatures. Your technique for the painting the skin would make me want to hire you!).
Please even if you don't get around to finishing for the challenge, I would love to see the end result of this. Great work!!

Tim