Efrem Zimbalist Jr. was 29 in House of Strangers when he played the character 'Tony Monetti'.
That was over 75 years ago in 1949.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
In 2014 he died aged 95, starring in 39 films in his career, 38 of those after House of Strangers was first released. If he were alive today he would be 105.
In House of Strangers, I think Efrem Zimbalist Jr. looks: