Post Office Seal Forerunner Cover, 1850. Folded letter from New York to Brookfield, Conn. with manuscript "Sept. 9th 1850 this letter opened by M. Throu by Mistake, H.S.P." endorsement at top, Very Fine. Estimate  $100 - 150. Prior to the introduction of thee repair seals in 1877, postal officials handled problem mail on an "ad hoc" basis. Inconsistent handling of such mail led to the introduction of the official seals. $0 (Image)