Now though Argentina did not sign the Treaty of Versailles they are there in an annex as one of the states invited to sign at a later date. And they were part of the League of Nations which followed; in fact they joined that on the 10th of January 1920, though they withdrew in 1921 as a protest to one of their resolutions being rejected, and only returned in September 1933.
Actually whilst researching this I found that the Kingdom of Serbs, Croats, and Slovenes also left the League of Nations at some point, but I am having a spot of bother tracing that.
The League of Nations remained throughout the Second World War, and was only dissolved on April 19, 1946. Though dissolved is too gentle a word, for its end was rather shocking, and it came in Geneva, when one of the original men involved with setting it up, Viscount Robert Cecil, gave a brief description of how it had done, and then ended with the exceptionally brutal statement - "The League is dead. Long live the United Nations."
This set is more optimistic, and in 1929 it must have seemed that it would fulfil its purpose of stopping another war. It appears in our original John Player reference book, RB.17, issued in 1950, as
97. 50 FLAGS OF THE LEAGUE OF NATIONS. Small cards. Fronts in colour. Backs in grey, with descriptive text. Home issue, March, 1928.
Colour variety : No.7 - Background of flag (a) dark blue (b) purple
This is again very much shortened in our World Tobacco Issues Indexes, to merely "FLAGS OF THE LEAGUE OF NATIONS. Sm. Nd. (50).
However, it is rather exciting to me that the code in the original World Tobacco Issues Index is 97, exactly the same suffix as in the original John Player reference book - for I cannot remember noticing that before.