The Huntington Library turned out to be one of the buyers Wednesday at a London auction conducted on behalf of the Roman Catholic Archdiocese of Los Angeles. The San Marino-based library purchased a rare English medieval illuminated manuscript from a cache of 46 medieval and Renaissance items from the Estelle Doheny collection. According to a Huntington spokesman, the purchase was "a once-in-a-generation opportunity, because manuscripts of this type don't come on the open market very often." The manuscript, purchased for about $180,000 with a monetary gift from the Dan Murphy Foundation of Los Angeles, "is unquestionably the most expensive single item the library has acquired" for 60 years, the spokesman said. The auction netted $9.5 million.