It may of some use to you to be able to eliminate one posssibility. Knowing
Twain had read DQ by 1860 (see Gribben's citation of Twain's admiration of
DQ in a letter from Twain to brother Orion in 1860), I wondered if there
might be some connection between that reference and the fact that Twain
owned a copy of Cervantes' EXEMPLARY NOVELS (London: Bohn, 1855, Walter
Kelly, trans.). I own that copy, which was inscribed by Twain in Hartford in
1875. It contains no other marks, other than Clara's much later shelfmarks,
to indicate whether Twain owned it before 1875 or where or when he might
have acquired it. It's worth noting that the dates of Twain's ownership
inscriptions are not always reflective of the date he acquired a particular
book, and it's also worth noting that there were 1870 and 1873 reprints of
this edition published by Bohn. If Twain had purchased this book in 1875, it
would seem he would have bought a more recent edition; on the other hand, he
did buy used books, including some at auction. It is possible the book came
from Livy's family, but the books I've seen from the Langdon family library
usually have stray marks of ownership that point in that direction. Finally,
I explored the possibility that perhaps Bohn issued this volume as a
companion to some edition of DQ, but a search of OCLC turned up no
translations of DQ by Walter Kelly, and no editions of DQ by Bohn. As I
said, this hardly answers your question, but it eliminates one direction of
inquiry.

But perhaps it opens another. Have you considered the possibility that
Twain's reading of Cervantes' short fiction, ca 1875, might also have
influenced the writing of HF?

Kevin Mac Donnell
Austin TX