Gorgeous! Thanks for sharing!
It's interesting to see the evolution of Cerebus' look over the years. One way to veryify the authenticity and a rough date of origin of the quick head sketches Dave did: If he lightly sketched out a circle before placing hte facial features, then it dates back from no to about the early 1990s (I saw him do this when he was in seattle in 1992). If the face is more elongatged, then it's from the '70s or '80s.
FYI, there's a lot of exclusive artwork posted at Cerebusfangirl.com.
--Claude Flowers