It's a Super Bowl tradition for the host owner - in this case, that'd be Indianapolis Colts kahuna Jim Irsay - to throw a party for friends and fellow NFL owners a few nights before the big game. Because Irsay is a bit of an eccentric, he used last night's VIP affair at the Indiana State Museum to show off a few items from his unusual collection of iconic keepsakes. None of these eclectic artifacts is more impressive than the 120-foot-long scroll/manuscript of "On the Road,'' the celebrated novel by Lowell-bred Beat writer Jack Kerouac. Irsay bought the document at auction a decade ago - he paid $2.43 million - but has only unfurled it once before, at the University of Iowa a few years ago. (The scroll is usually kept at Irsay's office at the Colts complex in Indianapolis.) "The scroll was done in 1951 and the book was published in 1957,'' explains Dale Ogden, who curated the exhibit and took us on a tour yesterday. "As any 60-year-old document that's been used and abused over the years - the end of the scroll was chewed off by Kerouac's roommate's dog - it's fragile.'' (Consequently, the scroll is being displayed beneath UV-filtering plexiglass and lights are not directly on the document.) The Kerouac manuscript is the centerpiece of the Irsay collection, but there are other eye-catching items at the museum exhibit, including guitars from George Harrison, Elvis Presley, Keith Richards, Bruce Springsteen, and Jerry Garcia's axe "Tiger.'' "Jim has over 60 guitars,'' says Ogden. "As an old, unreconstructed Deadhead, I'd seen 'Tiger' played several times, so it's cool to have it here.'' (It's a nice break from handling mastodon skulls, of which the Indiana State Museum has a few.) Don't care about guitars? Irsay's priceless paraphernalia also includes letters written by George Washington and Thomas Jefferson, Austin Powers's glasses, and the first draft of the script for "Monty Python and the Holy Grail.''