Domestic letter with perfin "B.T." in the stamp. The letter is franked correctly with 30 øre, which was the rate [...]

Domestic letter with perfin "B.T." in the stamp. The letter is franked correctly with 30 øre, which was the rate [...]
International letter with perfin "BD" in the stamp. The letter is franked correctly with 20 øre kr, which was the [...]
Domestic letter with perfin "B" in the stamp. The letter is franked correctly with 15 øre, which was the rate [...]
International post card with perfin "BOG." in the stamp. The post card is franked correctly with 35 øre, which was [...]