single used alongside Panama 1906 2½c Red orange (188) on United States 1904 2c Carmine entire, tied by January 24, 1907 Ancon duplexes, addressed to Ann Arbor, Michigan, light edge wear, although philatelic a very fine and attractive "three country" franking, illustrated in the Canal Zone Philatelist (Vol. 12, No. 3), ex-Plass