Cover franked with 1930 4c black & blue national issue and 1929 irregular marginal block of six 5c orange yellow SCADTA issue (SG 412 & 65) tied by BOGOTA SCADTA cds's. Addressed to PEDRO MIGUEL, CANAL ZONE with fine strike of 'PANAMA-COLOMBIA-ECUADOR USE THE SCADTA AIRWAY SYSTEM SAVES ABOUT 10 DAYS Information and stamps through BOYD BROS PANAMA CITY' Panamanian consular agents cachet in blue on reverse with BARRANQUILLA transit cds also on reverse. Very scarce.