Think there’s hidden treasure in dusty hard-covers or glossy paperbacks on your bookshelves? Bring them on Thursday to First Congregational Church on West Foster Street, where Kenneth Gloss, a Boston antiquarian book dealer, will deliver a talk titled, “Is There Value in Your Old and Rare Books?” The free event, sponsored by the Melrose Historical Society, will start at 7 p.m. Gloss is the owner of the Brattle Book Shop, which specializes in rare and old books. Printed materials from its archives, such as a sales brochure for the Titanic and a 1912 World Series score card, will be displayed during the talk. After his presentation, Gloss will give a free, verbal assessment of old books visitors bring with them. “New England homes are treasure-troves for old and rare books that have increased in values over the years,” Gloss said in a statement.