So Ill weigh in on this.
Simply because its a square image doesn't mean it was a square negative, nor peel apart.
The little marks atop are index marks that were used not only for manufacturing but processing.
Fox Photo used that system and had automated print machines, why you had Fox Photo ONE HOUR in place then. Fox was purchased by Kodak and their stamp went on the system.
I am NOT saying it IS a Fox Photo special, but it looks an awful lot like one.
My dad only shot his Minolta, and sometimes ordered square pics for certain purposes.
View attachment 260238
Anyone remember these?