Nigel Hawthorne was 27 in Carve Her Name with Pride when he played the character 'Soldier in Park (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).
In 2001 he died aged 72, starring in 63 films in his career, 62 of those after Carve Her Name with Pride was first released. If he were alive today he would be 95.
In Carve Her Name with Pride, I think Nigel Hawthorne looks: