Patrick McGoohan was 25 in Moby Dick—Rehearsed when he played the character 'A Serious Actor / Starbuck'.
That was over 69 years ago in 1955.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
In 2009 he died aged 80, starring in 46 films in his career, 44 of those after Moby Dick—Rehearsed was first released. If he were alive today he would be 96.
In Moby Dick—Rehearsed, I think Patrick McGoohan looks: