Wow.  Cool.  I got a response to my post about Burroughs (over at my blogger account, not here), from the editor/webmaster of the Burroughs tribute site group.  I thought I ought to mention what he told me, cause it's good info.  Only the first few Carter books are public domain, and most of the characters &c. are still copyrighted. 

Also, he mentioned two of Burrough's books that are considered some of the most pro-Indian pieces of the twentieth century:  The War Chief and The Apache Devil.  I didn't know about those, so thanks for letting me know.  And now I let others know.  Truly, the circle of life is grand, especially when it's a circle of literature, and not life.  ^_^