1950's Air Mail from Finland to West Germany

Helsinki -> Köln 18.11.1953

2nd weight class letter (21g-40g, valid 1.1.1953-31.5.1956) 40 marks. Air mail surcharge 3 marks/5g (24.10.1945-30.9.1957). The attached stamps match (55 marks) an air mail letter rate for a letter weighing 21g-25g. Correct rate. 

Helsinki -> Duisburg, 17.12.1952

The postal fee has been paid by a single 15 marks stamp. The 15 marks does exactly match the postcard rate of the period but then there is the missing air mail surcharge. Air mail surcharge was 3 marks between 24.10.1945 - 30.9.1957. It was possible to send greeting cards using a cheaper rate as printed matter (more on this here). The printed matter rate was 10 marks (<50g, 1.1.1952-31.7.1958). The 15 marks would be enough to cover the printed matter and air mail surcharge but would still be 2 marks overpaid. Nevertheless, the 15 marks M1930 stamp alone on a postcard abroad at that time period is still a rare occurrence. 

Helsinki -> Hamburg 25.11.1950

The combined face value of the attached stamps on the cover is 59 marks which does not match any possible combination of letter rates and air mail surcharges regardless of weight. As the stamps are all from the same Red Cross series published in 1949, it is safe to assume that the sender has overpaid for philatelic purposes only. 

Helsinki -> Duisburg 7.7.1953

Postcard rate (1.1.1952 - 31.5.1956) 15 marks. Air mail surcharge for postcards 3 marks (1.12.1948-30.9.1957). Correct rate.

Helsinki -> Duisburg 3.5.1953 

Letter rate to Germany was 25 marks between 1.1.1952 - 31.5.1956. Air mail surcharge was three marks for each five grams of weight between 24.10.1945 - 30.9.1957. The combined face values of the stamps are 37 marks which coincides with the rate for a letter weight of 15-20 grams. Correct rate. 

Helsinki -> Duisburg 7.9.1953

Letter rate to Germany was 25 marks between 1.1.1952 - 31.5.1956. Air mail surcharge was three marks for each five grams of weight between 24.10.1945 - 30.9.1957. The combined face values of the stamps are 31 marks which coincides with the rate for a letter weighing between 5-10 grams. Correct rate.

Helsinki -> Hannover 14.8.1951

Letter rate to Germany was 20 marks between 1.11.1949 - 31.12.1951. Air mail surcharge was three marks for each five grams of weight between 24.10.1945 - 30.9.1957. The postal stamps of the cover below coincide with the rate for a letter weighing 5-10 grams. Correct rate. The 20 marks blue was intended to be used as payment for letters abroad and the three marks grey was commonly used to cover air mail surcharges.

Helsinki -> Recklinghausen 4.12.1951

Letter rate to Germany was 20 marks between 1.11.1949 - 31.12.1951. Air mail surcharge was three marks for each five grams of weight between 24.10.1945 - 30.9.1957. The postal stamps of the cover below coincide with the rate for a letter weighing 0-5 grams. Correct rate. The 20 marks blue was intended to be used as payment for letters abroad and the three marks grey was commonly used to cover air mail surcharges as is shown here.