New York City's oldest neighborhoods are downtown, where scores of timeworn ads have improbably survived for decades. These "ghost signs" hold the secrets of businesses and products that disappeared decades ago. Journalist and television producer Frank Mastropolo tells the stories of more than 100 vintage signs of businesses that have vanished in a new book, "Ghost Signs: Clues to Downtown New York's Past." This tour offers a few of the book's ghost signs and some new additions.