Insufficiently paid for Air Service – Sri Lanka Aerogramme 1966.
Ceylon Issued a 30 Cents Aerogramme with the coat of arms design in 1966 when airmail rates from Ceylon were 30 Cents. This aerogramme was used in 1968 when the aerogrammes rates were revised to 50 cents and it was marked as “Insufficiently paid for Air Service” by Postal authorities and posted /delivered through land/sea route.
Stamp Digest 