"The Waldorf Astoria hotel in Manhattan is known for its grand public spaces, like its two-tiered ballroom and vast lobby. But upstairs, in a windowless corner of the hotel's administrative offices, Deidre Dinnigan toils in a cramped room not much larger than a closet. Ms. Dinnigan, the hotel's archivist, is responsible for cataloging and researching more than 4,000 objects, from filigreed brass room numbers to yellowing advertisements from the 1950s. ,,, The 123-year-old Waldorf Astoria is one of the few hotels with an extensive archive, and possibly the only one to have its own archivist. But the future of Ms. Dinnigan's position, and the collection that she oversees, is uncertain. The hotel, which was bought by a Chinese insurance company two years ago for a record $1.95 billion, is to close in the spring to undergo a conversion. Most of the 1,413-room premises will be turned into luxury condominiums, with a much smaller hotel component."