1 Jul 1961 to 31 Dec 1965
US foreign surface letter rate 11 c
US Conversion rate 1 US cent = 3 goldcentimes
Swedish conversion rate 1 goldcentime = 1.7 öre
US handstamp shows amount to pay in goldcentimes, normally double deficiency.
In Sweden the indicated amount multiplied by 1.7 and rounded up to nearest 5 öre was marked on the item. The amount due was normally paid by affixing stamps on the item.
Aerogramme with 10 cent. Correct rate 11 cent.
US due handstamp indicates double deficiency 2x3x1=6 centimes. Amount due
in Sweden 1.7x6=10.2 öre rounded up to 15 öre. The amount should
normally have been affixed in postage stamps but the due has probably been
ignored.