This is Bill Nighy. He is 63. The age of Plutarch is never told, however I think Bill could portray him quiet well.
Plutarch Heavensbee is meant to be the replacement Head gamekeeper, taking the place of Seneca Crane. He becomes a commander of the rebel forces of District 13 in Mockingjay. In catching fire he first meets Katniss at the Dance floor in the Capitol when they are at Snows Mansion. He gives her a slight hint at the party of what the games will be like when he circles his thumb a room the numbers on his pocket watch and says " Never lose track of time". Later on during the Quarter Quel, Katniss and Wiress discover that the arena is one big clock. Each hour begins a new horror.