right stamp in horizontal pair (positions 89-90), used alongside 1904 2c Rose (10.B, position 36) and 1906 2c on 1p Lake block of six (17, positions 88-90, 98-100), all tied by July 20, 1906 Ancon datestamps to registered Dr. Perry cover to Birmingham, Alabama, Cristobal boxed registry and stamp, very fine and likely unique on cover, this example of the "P nama" variety is unusual as it has selvage at right which does not correspond to any of the listed positions