Chittum has a web site, but it has not been updated for a couple of months.
The web site:
http://www.firebaseskull.com/
There you will find this explanation:
"Notice: Effective immediately August 21, 2005; I am no longer able to maintain this website due to a family health emergency, and a totally buggy computer-Even my e-mail is out of order. I will probably resume updates only after several month at the soonest. I will continue to fill snail mail orders for Sgt. Skull's field manual for the practical warrior, and for Sgt. Skull's big list of NWO Heroes
Thanks for visiting and good luck.
Tom Chittum "
He states that he has one copy of "Civil War II" left. It is signed and he will sell it for $100.
If you go to Amazon.com you can find the book from "other sellers" ranging from $39.79 up.
I bought my copy many years ago from some fellow in Arizona. I can't give any advice on the ethics of downloading it.
Enkidu