William Holden was 34 in Stalag 17 when he played the character 'Sgt. J.J. Sefton'.
That was over 71 years ago in 1953.
In 1981 he died aged 63, starring in 85 films in his career, 53 of those after Stalag 17 was first released. If he were alive today he would be 106.
In Stalag 17, I think William Holden looks: