Yes Peter, I noted that the 1917 is listed as Civil War coinage. These appealed to me in particular because of the three different designs covering a relatively short period of time (although 1916, 1917 & 1919 would have been even better ).
Thanks as always for pointing me at the extra information.
Notice on the Provisional Government coinage that the Russian arms are retained but the crown has been removed.
I'm slightly confused by the term "liberated" issue with reference to KM 21. For a start, Finland wasn't under an occupation from which it could be liberated; it declared independence from Russia before the Civil War and the Russians, whether tsarists, Mensheviks or Bolsheviks, were in no position to do anything other than recognise it (which Lenin explicitly did). In the prejudiced language of the Civil War victors, Helsinki was indeed "liberated" by the right-wing White faction (with help from the Germans) from control by the Red (Communist) faction, but it was a case of Finns fighting Finns, not occupation by a foreign power.
Secondly, although I can't find a definitive answer to this question, the style and the legend on this solitary 5 penniä coin suggests to me that it is the product of the Red government, not the White or postwar governments. The text "Kansan työ, kansan valta" means "work for the people, power for the people" which is hardly a suitable slogan for the bourgeois Whites. Also the fact that it is solitary is telling: the provisional government of Kerenski managed to issue the full range of denominations, but this 5 penniä is on its own. The Finnish Civil War was mercifully short (compared to similar conflicts in Russia and later in Spain) and control by the Reds of anything approximating to state apparatus was very short-lived.
If you're interested in the background to the Finnish Civil War, I can recommend Kjell Westö's novel Där vi en gång gått
, which I think is available in English as well, probably called "Where we once walked" or similar. It covers the story of families from both sides of the divide. It has also been made into a film