I hope you don't mind me chipping in with a few details about this one, Phantom. This was for a television pilot written and directed by Bill Malone that was titled "Holmes and Walston". Robby the Robot had the brain of Sherlock Holmes and his assistant, Walston, was played by Jerry Mathers. The man in the Gort suit is DPS handyman Kermit Eller, who went on to wear the Syngenor suit for Malone's "Scared to Death". Eller was also the man in the Darth Vader costume for the Southern California personal appearances in the late '70s (including the Oscars and the Grauman's Chinese Theater footprint ceremony).
Thanks for the info Lee! In addition, I was told yesterday that Bob Short is in the photo, pictured on the right hand side.