I also thought he was mid to late 70’s. But he’d had a hard life and myriad health issues, all of which can age a person.
I've seen a few videos of him (since his passing) with a walker and folks helping him move about. When he was at the podium or even talking to the people during the riots, his demeanor wasn't that of a man with health "issues". Indeed, health issues can slow ya down. Rest in Peace, Mr. Chairman.