Is the voiceover for the station identification/sign-off at the end Ronald Reagan? I could imagine he recorded that sort of thing in the 1960s.
I think the thing I miss most about late night television from this era were overnight movies on those local TV stations that didn't sign off every night. I was still in elementary school and didn't get to see that much late night TV back then but I did have a small Radio Shack black-and-white TV/radio combo next to my bed that I would sometimes watch "quietly" if I couldn't sleep.
I uploaded a video like this once, to YouTube, from one of my 80’s tapes channel flipping, and it got a lot of comments from people searching for their birthdays.