This will seem like ancient history, probably, but Professor Daniel M.
McKeithan of the University of Texas at Austin published a book in 1958
titled COURT-TRIALS IN MARK TWAIN AND OTHER ESSAYS (The Hague: Martinus
Nijhoff). He tried to cover the most significant examples of Twain's
interest in the administration of justice.
Herbert Feinstein wrote an article on Twain copyright battles--"Mark Twain &
the Pirates," HARVARD LAW SCHOOL BULLETIN 13 (April 1962): 6-18.
These are a start, anyway.
Auburn University Montgomery