Double studio portrait of the same man on one negative

Double studio portrait of the same man on one negative. On the left picture, a man wears a shirt. He does not look at the camera. On the right photo, the man is dressed in the same way, but faces the camera. No backdrop. Date of original material: [1951]. Size of original print/negative: 3 ½ x 2 ½ inches (2B). Format of original material: Glass plate black and white negative.