thanks again to the greatest blog in the entire world for re-focusing my attention on John Charles Daly, Arlene Francis, Bennett Cerf, Steve Allen [he didn't have to die!], and so many others.
just look at this list of Mystery Guests, as noted here:
The first year as a Sunday night staple, the mystery guest roster was an eclectic one. Bob Cummings was the first. Also from Broadway, films and TV: Joan Blondell, Douglas Fairbanks Jr., Sam Goldwyn (on a special Saturday night telecast), Sir Cedric Hardwicke, Celeste Holm, Boris Karloff, Veronica Lake, Margaret O'Brien, Phil Silvers, Gloria Swanson, Rudy Vallee, Ethel Waters and Ed Sullivan. From sports came Leo Durocher, Bob Feller, Slapsie Maxie Rosenbloom and Sugar Ray Robinson (baseball legend Jackie Robinson did the same for game shows as he did for the major leagues when he was the first black to appear on a game show Aug. 16, 1950). Music brought Benny Goodman, Oscar Levant, Lauritz Melchior, Richard Rodgers, Margaret Whiting and (on New Year's Eve) Guy Lombardo. From the entertainment media entered Hedda Hopper as well as Sullivan.