Cookie Monster's Early Work

The New York Times just ran an article on “Jim Henson's Fantastic World,” an exhibit at the Museum of the Moving Image in Queens. (Has anybody been? I'm sensing a field trip.)
One thing The Times mentioned was the origin of Cookie Monster, who evolved from The Wheel-Stealer—a snack-pilfering puppet Jim Henson created to promote Wheels, Crowns and Flutes in the 1960s.
This puppet later was seen eating a computer in an IBM training film and on The Ed Sullivan Show.
A purple puppet named Arnold looked very Cookie Monster-y in commercials for Munchos. Then came Sesame Street.
And while we're on the subject of Cookie Monster's background, as our friends at Muppet Wiki point out, Cookie Monster said (well, sang) in 2004 that before he started eating cookies, his name was Sid.