Horst Kruse does an excellent job putting together information relevant to SLCs
 pseudonym; the article Larry Marshburne cites is probably the best available.
 Kruse's argument for SLCs story of the origin of Mark Twain depends on several
 coincidences and ignores the two or three Western reports confirming the bar
tab origin.  Much as I like to marshall coincidence as evidence, it is hard to
stick with the Sellers' river-notes version in the face of witnesses to the
contrary.  SLC might have told the river-note origin so often that he believed
it, but I don't.  He had good reason to suppress the bar tab version during his
 courtship of Livy Langdon; he also usually stuck with a false story when it
made a better tale than the true one.
 
On the Oscar WIlde connection: Charles Neider's _Papa_ reprints perhaps 20% of
Susy Clemens' correspondence with Louise Brownell.  I am sure a quick perusal
of Susy's letters from Bad Neuheim will include the reference.  Copies are on
file at the Mark Twain Papers; the originals are at Hamilton College.