Behind the scenes stuff of any substance was notoriously hard to come by the first couple years. Even the Making of Star Wars tv special dodged interviewing the men behind the masks.

Seeing Prowse unmasked in a tabloid magazine article was something of a victory for me as kid, what with my peers thinking Threepio was some sort of audio animatronic figure. ;)

IIRC, Ray Harryhausen never allowed photos to be taken while he was actually animating, so it doesn't surprise me the ILM guys would fake it for Cronkite.

Uncle Walter would later pay a visit to the game grid.

http://www.youtube.com/watch?v=O2IOvFPgi2s