Rarity depends on the mintage and the number of specimens still in circulation.
1914Netherlands 1 gulden 1914
1915United Kingdom 1 Penny 1915
1916Italy - 2 lire 1916 R - Vittorio Emanuelle III
1918Germany 5 pfennigs 1918 A
1918Portugal 1 centavo 1918
1918Portugal 2 centavos 1918
1919Denmark 10 öre Christian X 1919 ♥ HCN
1919Portugal 4 centavos 1919
1920France 25 centimes 1920 - Lindauer
1920France 5 centimes 1920 - Lindauer large module
1921France 10 centimes 1921 - Lindauer
1921Germany 50 Pfennig 1921 A
1922France 2 francs 1922 - Good for 2 francs (Chambers of Commerce)
1922Germany 3 MARK 1922 A
1923Germany 200 Mark 1923 A
1923Germany 500 MARK 1923 A
1924France 50 centimes 1924 - Good for 50 centimes (Chambers of Commerce)
1924Germany 2 reichspfennig 1924-F
1925Germany 10 Reichspfennig 1925 D
1925Portugal 20 centavos 1925
1927Italy - 5 lires 1927 R - Vittorio Emanuele III
1927Portugal 5 centavos 1927
1927United Kingdom 1 Penny 1927
1928Ireland 6 pence 1928 - Irish Free State - Irish Wolfhound
Germany 63
France 47
Portugal 21
Ireland 19
United Kingdom 18
Norway 16
Guernsey 11
Netherlands 10
Italy 9
Canada 7
Mexico 7
Isle of Man 6
Belgium 5
Denmark 2
Greece 2
Switzerland 2
Colombia 1