BUFFALO, N.Y. – A collector credits a hunch with helping him land one of just 100 sheets of stamps recently issued by the United States Postal Service featuring a corrected version of its rare and famous error, the 1918 "inverted Jenny." Art Van Riper bought the stamps in Waverly, N.Y., after reading that the Postal Service had printed a new batch of inverted Jenny stamps celebrating the 95-year-old edition that, by mistake, featured an upside-down biplane. He also read that, as a way to draw more people into stamp collecting, the Postal Service randomly distributed 100 sheets featuring the plane...