Amid all the to-do over Ken Burns, your inquiry about available
editions of -No. 44- seems to have become lost.  I didn't know that
the Gibson edition was no longer available in paperback.  I have
used the Mark Twain Library (UCal Press) editon edited by John
Tuckey that is still available (ISBN 0-520-04545-9).  When my
class bought it, a paperback, the book store price was $16.  It
contains only -No. 44, The Mysterious Stranger-, however, not -
Chronicle- and "Schoolhouse Hill."  There are "Explanatory Notes"
and a brief Foreword by Tuckey. -The Chronicle of Young Satan-,
printed as
-The Mysterious Stranger- (the version published in 1916), is
available in any number of relatively inexpensive paperbacks.
Using one of them, you would need to explain that the ending had
been added and altered and that other material had been deleted or
altered (including the creation of a new character, the Astrologer,
and the tranferral of words and actions to him from another, Father
Adolph) by Duneke and Paine.  Other than Gibson's book, I don't
know where "Schoolhouse Hill" is available.

At least, you can get the non-Paine-Duneke vesion of the final
novel in paperback.

Good luck.
John H. Davis, Ph.D.
English Division
Chowan College
Murfreesboro, NC