Got these for $14 for the lot. Shanghai, 1930, 20 customs units Numista says these were for customs payments but during the chaos in the start of WW2 they were eventually also used in general circulation. I like the financial script numerals for the denomination in the corners 貳拾 = 二十.
Germany 1 Rentenmark 1937 Not sure why these are designated 1 Rentenmark instead of 1 Reichsmark\ On coins, at least, I thought the Rentenmark designation was only used in 1923-4.
Last one: Canada 2 Dollars 1954, No "Devil's Face" Apparently an early version of the QE2 portrait had a random pattern in her hair that looked a bit like a devil's face. So they revised the portrait.
The Rentenmark was meant to be temporary and it was officially replaced as the national currency by the Reichsmark in 1924, but both notes remained legal tender. In 1937, the German government utilized the Rentenbank to issue 1 and 2 Rentenmark notes because the Reichsbank did not issue denominations lower than 5 Reichsmarks. Both notes included an image of a sheaf of wheat on the back, the emblem of the Rentenbank. When France, Britain, the United States, and the Soviet Union placed Germany under allied occupation in 1945, the Deutsche Mark became the official Germany currency, but the Rentenmark and the Reichsmark both remained in circulation until 1948.
Basswarwick is correct that the Reichsbank was not authorized to issue notes less than 5RM. The last part is wrong, however. The Allied Military Mark was introduced in 1944 at par with the RM. The RM and AMM remained in circulation until the 1948 Currency Reform introduced the DM, although no new RM notes could be printed because the Russians refused to allow it.
They're from the original Karsh portrait & were printed for 2 years (till 1956) so they're not that tough, hard to come by or rare. They're just popular worldwide & look a lot nicer than the modified version (not sure why but you have to place side-by-side to appreciate the differences).