Lot
1480 
1869, 3¢ ultramarine, single and strip of three, tied by three strikes of squared six-section grid Foreign Mail cancels on 1869 cover to London, England, purple "Phil'a Paid All Aug 3" exchange office cds, red London Paid (8.14) arrival cds; strip light corner crease, Very Fine. Scott No. 114 Estimate $300 - 400.
Philadelphia was the only exchange office to use this distinctive purple cds ink on foreign mail.