While watching Sesame Street Old School, I noticed that before each episode, there was a short little animated bit that featured the episode number (like the first episode had that claymation bit with those two creatures entering Sesame Street, or for season four and five having that woodpecker pecking "Sesame Street" on the tree trunk), and at the end of each episode there's still-shot of a character (or two) holding the Sesame Street sign, and then another one of a different character (or two) holding a funky Children's Television Workshop sign when the disclaimer is head "Sesame Street is a production of the Children's Television Workshop". How long did those last? Because apparently they were long gone when I was first introduced to Sesame Street in the very early 90s.