Also countries from the Caucuses to Central Asian (Armenia, Azerbaijan, Kazakhstan, Kyrgyzstan, Tajikistan, Turkestan, Uzbekistan) held by Russia/USSR.
I've re-evaluated and forgot to include:
Nigeria (GB)
Somalia (IT, GB)
Djibouti (FR)
Pakistan (GB)
Afghanistan (independent)
UAE (GB, as the Trucial States PU'd with Qatar)
Qatar (Trucial States, under GB)
Bahrain (GB)
Half of Yemen (GB)
The Islamic world also lost a member due to the reunification of the Yemeni Arab Republic and the Yemeni People's Democratic Republic
If there is no dispute over 12 vs 50, then what are we talking about? What question do you want me to answer? What are the muslim majority countries? You don't know how to use google?