And because that second clip turned out to have been posted by Alan Light—no, not the Spin magazine editor-in-chief Alan Light, but rather the Alan Light who founded The Buyer's Guide to Comics Fandom—I ran across the fascinating (for those of us who bleed four-color ink) video below.
It turns out that on June 18, 1977, World Color Press held a celebration it called "Magazineland USA." World Color Press, located in Sparta, Illinois, printed all of the comic books at the time, and when the company threw open its doors for a tour, Light was there with his 8MM sound camera.
When I press my nose close to the screen, I swear I can smell the ink.
Phil Seuling, who ran New York's early comic conventions, can be seen at the 1:00-mark complaining about how non-fans were mistreating the books he'd brought for sale.
Wish I could have been there!