Stephen McHattie was 22 in The People Next Door when he played the character 'Artie Mason'.
That was over 54 years ago in 1970.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 77, and has starred in 114 movies in total, 113 of those since The People Next Door was released.
In The People Next Door, I think Stephen McHattie looks: