In May, 1898, Kemble accepted Bliss's offer to make new illustrations for
Twain's 1899 collected works. The illustration you cite appears at p. 93 of
PW in the 1899 edition. Those illustrations were used by Harper after they
acquired the rights to Twain's works, but were moved around in the text
after 1903.  I have that letter Kemble sent Bliss, plus one of Kemble's
original drawings for the 1899 edition of HF (one of four new drawings he
did for that work), one of Kemble's original 1885 drawings for HF, an
archive of copyright and publisher's's documents relating to the 1899
edition, and original drawings by other artists for the collected edition,
and even Bliss's ink-stained wooden crate that held that held the printing
plates for the 1899 HF.  There could be something in the archive of
publisher's documents on PW that could be of use to you --it's mostly
contracts or copyright papers. No original art work for PW; I have some for
FTE, $30,000 BEQUEST, and P&P; maybe others. Happy to look around this
weekend, if you wish.

Kevin Mac Donnell