Was Blank Check the first game show to regularly display different names & letters on eggcrate displays? Since Price is Right only used eggcrate displays on the Showcase podiums & Card Game to spell out "OVER", I would hazard a guess that those were only signed/wired for that word only.
Oddly enough, it would be Art's next game show that would go one step further with "scrolling" alpha-numeric eggcrates on "Magnificent Marble Machine".