Wow, that is the only article I can find that says he went to Kenya in 1983. Everyone else says 1987 or 1988.
“But how much could the Old Man’s estate be worth?” “Not much. Maybe a small government pension. A piece of worthless land. I try to stay out of it. Whatever is there has probably been spent on lawyers by now. But you see, everyone expected so much from the Old Man. He made them think that he had everything, even when he had nothing..."
...For the briefest moment I sensed Mark hesitate, like a rock climber losing his footing. Then, almost immediately, he regained his composure and waved for the check. “Who knows?” he said. “What’s certain is that I don’t need the stress. Life’s hard enough without all that excess baggage.” We stood up to leave, and I insisted on paying the bill. Outside we exchanged addresses and promised to write, with a dishonesty that made my heart ache. When I got home, I told Auma how the meeting had gone. She looked away for a moment, then broke out with a short, bitter laugh. “What’s so funny?” “I was just thinking about how life is so strange. You know, as soon as the Old Man died, the lawyers contacted all those who might have a claim to the inheritance. Unlike my mum, Ruth has all the documents needed to prove who Mark’s father was. So of all of the Old Man’s kids, Mark’s claim is the only one that’s uncontested.” Again Auma laughed, and I looked up at the picture hanging on her wall, the same picture pasted inside Ruth’s album, of three brothers and a sister, smiling sweetly for the camera..."
If you read carefully, you will see he must have been in Kenya BEFORE THE ESTATE WAS SETTLED.