Countries that no longer exist from the 1950s to this day

Also, there's some missing ones. Serbian Krajina and Herzeg-Bosnia should probably be included if the other Yugoslav Wars quasi-states are there, the Republic of Benin was a short-lived Biafran ally/puppet during the Nigerian Civil War, Tanganyika and Zanzibar both were independent for a few years in the early 60s before uniting into Tanzania, there's a strong case to be made for Rhodesia's inclusion (although it also could be considered a previous government of Zimbabwe), the Islamic Emirate of Badashkan is basically the same scenario as Kumar, South/Free Lebanon, Saarland, the Maqis of Fizi, and possibly more I missed.