Rich,
The close-ups really show how hard you worked on this model. Excellent texturing! A realistic model is a massive undertaking and you've done a very good job so far.
There are a few areas that could use some tweaking. The outside corners of the eye sockets seem pulled back too severely. Maybe the indentation can be softer. Also, the way the nostrils blend into the moustache area seems too soft. There is "usually" more of a division between those areas. Your live model may not have that, and if not, please disregard.
Thanks for sharing your work,
Jim