If what I'm about to show is already well known, forgive me but I found this interesting enough to share. With Whew! finally resurfacing on Buzzr this past year, including the 3rd pilot with Maggie Brown, we're now able to see what hasn't been seen on TV in over 40 years. That being said, there are presumably at least 2 other pilots we've never seen. I just came across an old CBS promo someone uploaded that includes Beat the Clock, Whew!, and The Price is Right. Most of what's shown is pretty unremarkable, but one blink-and-you'll-miss-it clip caught my eye that is clearly from one of the other pilots. Here's the video for those interested.
Here are some side by side comparison shots that show this is clearly from one of the other pilots. The first shot is from the promo, the second from the Maggie Brown pilot, and the third from the series premiere just for reference to make the differences more apparent.



Note the similarities to the Maggie Brown pilot: The clock, the smaller screens on the villains, no movable arms, no eye holes, Alphonse has his machine gun, Nero's bigger nose, etc.
Edit: I also found this upload from 2013 that includes clips from one or possibly both of the other pilots, including the same clip from the above promo.
Thanks to The Game Show Pilot Light and Wink Martindale's upload of the Maggie Brown pilot, we know it was taped December 4, 1978. At least one of the other pilots must have taped the previous day as evidenced by the existence of
this ticket. I was unable to find anything else that's clearly from one of the unseen pilots as any promo images I've found are either from the series itself or feature Maggie Brown. I suppose my questions to anyone out there who may know are as follows: Does anyone know if the tapes of the other pilots still exist? Does Fremantle have them and could therefore potentially show them later down the line? Is there anymore known material from the unseen pilots floating around out there whether it be video, stills, or otherwise? It would seem unlikely based on what little I was able to find but sometimes you gotta go for the long shot.