When I bought the Belgian Congo collection, I also bought a similar collection of Ruanda-Urundi. It would have been rude not to have worked on this lot. The collection was largely complete and in the same excellent quality as the Congo. It seems strange that equivalent stamps in Ruanda are less highly catalogued than those from the Congo. The Ruanda stamps are probably scarcer but they are probably less in demand. 

When I sorted the South Africa recently, I did not include the 1964-72 definitives. SG now lists them as two different watermarks. They have now been sorted and can be seen in my list for South Africa.