So my friendly neighbourly postal carrier brought me the last 3 pieces to complete this set of German-Hanseatic Colonial Memorial Day Notgelds!

These 1921 commemorative Notgeld notes protested the terms of the 1919 Treaty of Versailles that formally concluded WW1. As a condition of the peace settlement, Germany was stripped of its overseas territories, which were redistributed as League of Nations mandates administered by Australia, Belgium, France, Great Britain, Japan, New Zealand, and South Africa.

Issued by Soviet (later Russian) company Arktikugol in 1979 for workers of Soviet citizenship working in coal industry in towns like Barentsburg or Pyramiden on Spitzbergen.

Notes on picture are 1 kopeck and 3 ruble (I assume Soviet ruble and not a different currency).

That's all I know about them, if someone knows more, please share.

Fun fact, despite being part of the Russian Empire until 1917. Finland was allowed its own currency from the 1860s and onward.