If the videos are indeed so old, then probably they were not intended for customers but for the internal training of IBM employees, which would match the "CONFIDENTIAL" label.
Indeed, he actually adresses that in the first video
>This presentation is one of a series which is intended to present you the systems engineer and salesman some of the advantages of Systems/360
Indeed, he actually adresses that in the first video
>This presentation is one of a series which is intended to present you the systems engineer and salesman some of the advantages of Systems/360