The one I have here is from '69-'74, and note that it's still certified "U", it simply starts with a verbal notice that "these early Sesame Street episodes are intended for grownups and may not suit the needs of today's preschool child," so it's a pretty mild warning. Milder than I remembered actually.

I found an article talking about it. It's pretty mild stuff, but an interesting illustration of how what we consider appropriate changes in all kinds of small ways:

> What parent today would want their child to see kids running through a construction site or jumping on an old box spring? Scenes like the ones included on the new DVD would probably not make it into today's program now.

> "We wouldn't have children on the set riding without a bicycle helmet," Rollins Westin says.

> And what's that little girl doing with that man?

> "In the very first episode, Gordon takes a little girl's hand who he's just met on the street, befriends her and takes her into his home to give her ice cream," Rollins Westin said. "That's something we wouldn't do on the show today."

(From https://www.cbsnews.com/news/sesame-street-for-adults-only/ )