Bruce-- You may want to contact the Smithsonian (ask for the curator/person in charge of the vast permanent exhibition of printing presses at the Museum of American History) or the Newseum in Virginia. It probably wouldn't hurt to contact Tom Muzzio, the current publisher of the Virginia City Enterprise. He's proud of his paper's Twain connections and may be able to answer some of your questions. I do know, however, that Mergenthaler's linotype didn't come into use until 1884 or so, utterly eclipsing the competing typesetter a fellow named Paige was trying to perfect, with considerable financial backing from Clemens. Hope this helps! Good luck! Kathy O'Connell Hartford, Conn.