Walter Sparrow was 41 in Zeta One when he played the character 'Stage Manager'.
That was over 54 years ago in 1969.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
In 2000 he died aged 73, starring in 17 films in his career, 16 of those after Zeta One was first released. If he were alive today he would be 97.
In Zeta One, I think Walter Sparrow looks: