Why do you think that the presentation was done in 1964?
On Youtube there is no mention about the date.
OS/360 was announced in 1964 but it was first delivered more than a year later.
I doubt that such presentations were done about a product that no customers could use and which might still be changed until the first deliverable version.
So I believe that it is unlikely that this presentation was done earlier than 1965 and it is likely that it was not done before 1966. The first OS/360 versions were delivered in November/December 1965.
The earlier video from the series, GG46955 IBM SYSTEM/360 READ ONLY STORAGE, is dated to 1964
https://www.youtube.com/watch?v=gcc_SAy-I80