Domestic letter with perfin "N.K.K." in the stamp. The letter is franked correctly with 15 øre, which was the rate [...]

Domestic letter with perfin "N.K.K." in the stamp. The letter is franked correctly with 15 øre, which was the rate [...]
International registered letter with perfin "N.D.&K." in the stamps. The letter is franked correctly with 2 x 15 + 2 [...]
Domestic letter with perfin "LB" in the stamps. The letter is franked correctly with 10 + 20 øre + 2 [...]
International letter with perfin "Ø.K." in the stamp. The letter is franked correctly with 30 øre, which was the rate [...]