1 July 1875 to ca 31 Mar 1879

US foreign surface letter rate 5 c
US Conversion rate 1 US cent = 5 goldcentimes
Swedish conversion rate 1 goldcentime = 0.72 öre. (Rates not completely clear, may also be 0.8)
US marking shows the value of stamp affixed in goldcentimes.
In Sweden double rate for the item less the value of the US stamps affixed is charged. The amount due was paid by affixing postage due stamps.

Letter with 3 cent. A 3 cent US stamp has been affixed but later removed. 15 indicates the value of the stamp in centimes (5x3=15 centimes). Sweden has charged the double letter rate 2x20 öre less the value of the US stamp 0.72x15=11 öre; 40-11=29 öre.

Another example of the same rate