Sam Shepard was 25 in Brand X when he played an uncredited character.
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).
In 2017 he died aged 73, starring in 74 films in his career, 73 of those after Brand X was first released. If he were alive today he would be 80.
In Brand X, I think Sam Shepard looks: