In this week's version of Brain Pickings, Maria Popova discusses the Autobiography, volume 2, and includes other items of interest, including a Twain inscription from a book in Kevin MacDonnell's collection, plus links to other Twain-related works [including a link to Kent Rasmussen's excellent recent publication, which is well worth your time if you have not read it yet].
http://www.brainpickings.org/index.php/2013/10/08/religion-autobiography-of-mark-twain-volume-2/
Pat Ober