In response to the question as to whether MT was familiar with
Bulwer-Lytton--yes. Several of his books were in Twain's library, with
notations indicating he had read them. He doesn't seem always to have been
greatly impressed by him. Apparently Paine once said that Twain hadn't read
Lytton--"couldn't read him at any length" but Gribben seems to think that
Twain's extensive marginalia proves otherwise.
I got the Gribben volumes from the UIUC library and am loath to return
them. It's perfectly fascinating to see what a variety of books Twain
owned, and, most likely, read.
Athan