Double studio portrait on one negative

Double studio portrait on one negative. Two portraits of the same man, wearing a shirt. On the left picture, he is slightly slanted and does not look at the camera. On the right photo, he faces and looks the camera. No backdrop. Date of original material: [1959-60]. Size of original print/negative: 3 ½ x 2 ½ inches (2B). Format of original material: Glass plate black and white negative.