By 1974 I think the concept of selling peoples is not acceptable, but earlier?
After the British Ultimatum and Portugal becoming a Republic would circumstances have them sell off colonies to the British, Germans and/or French? It is my understanding that before the Great War the British and Germans floated a partitioning of Spanish colonies, would a similar notion arise had it occurred once Spain is no longer on the map? I think the British want Macao and everything in India, the Germans would want Angola to push closer the linking SWA and Kamerun, or at least building upon SWA, there are some islands off Kamerun the Germans likely want but France might like, Mozambique appeals equally to the French and British, etc. In a no Great War scenario it likely strengthens the colonial system and deepens the hold of three peer Great Powers in Africa. Or post Great War that puts these colonies on the table for whatever alternative ending and divvying of spoils one imagines. To the extent one likes to re-imagine the colonial system I think such change needs to happen before the 1920s if a war and maybe the 1940s without?