May 1936: This item, airmailed to Baron Franckenstein in London on 27 May 1936, has curiously mixed cancels.

The block of four 35gro is cancelled 1 WIEN 9; the pair of 8 and the 4 with T Z ST (without the year: this is common); and there is a WIEN FLUGPOST in the bottom corner. The red mark in the top left looks like 1/V. Total franking 160. Surface postage is 60 for 20gram letter plus 35 for each further 20gram. Air seems to be the 20.4.1936 rate, which is 40 for 20gram plus 20 per further 20grams. So a 20gram would be 100 and a 40gram 60+35+40+20=155 - so it's overfranked by 5 and the 4 stamp wasn't needed.