Call the listed number for ultra-tough-to-score-reservation restaurant Rao’s and you’ll get a prerecorded message: “Thank you for calling Rao’s. We are currently booked until the end of 2009. We are not taking any reservations for 2010.” But the glory and the baked ziti could be yours if you’re free on December 28 at 7 p.m., sharp: A four-top has opened up as a charity-auction item. The reservation is the big draw, of course, but the winner also gets a $300 house credit toward the evening’s check. The Nourishing Kitchen, an East Harlem charity located a block away from Rao’s, will benefit. The group serves 6,000 healthy meals a year, conducts free nutrition classes, and operates three local community gardens. The bid right now is at $1,525, and the auction ends in three days. Do we hear $1,600?