In all that information that you have shared it keeps saying that Kikuyu tribesmen were arrested for being involved in the Mau Mau activities. 0’s alleged grandfather was Luo. There was no mention of Luo in what you shared. Could this story about the grandfather be just another piece of the 0 mythology? Have you come across anything that indicates that Luo members were also part of the rebellion?
Mau mau rebellion
Despite plenty of overt pressure on Kenya’s colonial authorities, the real independence movement was underground. Groups from the Kikuyu, Maasai and Luo tribes vowed to kill Europeans and their African collaborators. The most famous of these movements was Mau Mau, formed in 1952 by the Kikuyu people, which aimed to drive the white settlers from Kenya forever. In true African fashion, the Mau Mau rebellion was a brutal war of attrition on white people, property and ‘collaborators’. The various Mau Mau sects came together under the umbrella of the Kenya Land Freedom Army, led by Dedan Kimathi, and staged frequent attacks against white farms and government outposts...
http://www.lonelyplanet.com/kenya/history#44020