Steven Berkoff was 20 in I Was Monty's Double when he played the character 'Minor Role (uncredited)'.
That was over 66 years ago in 1958.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 86, and has starred in 94 movies in total, 91 of those since I Was Monty's Double was released.
In I Was Monty's Double, I think Steven Berkoff looks: