The Columbo writers already poked fun at the young genius Stephen Spielberg (Spelberg) in Mind Over Mayhem, but I think the older Spielberg also got a nod as Alex Brady.
Max Barsini - Pablo Picasso (He was notorious with women)
Sean Brantley - Hugh Heffner
Nicholas Frame and Lillian Stanhope - Richard Burton and Elizabeth Taylor.
Ken Franklin and Jim Ferris - Richard Levinson and William Link.
Levinson said in Columbo Phile, "The fun we all had that this was Link and Levinson that this show was about: two mystery writers. Everyone would say, 'Which of you is the writer and which of you is the talker?' Of course it's not us literally but we thought it was a novel idea for a show. There was a constant string of Link and Levinson jokes during that show." The very names, "Franklin and Ferris" were meant to evoke the same alliterative ring.
Astaire-Rogers is I'm sure the best generic connection in terms of a famous real-life dance team. Its easier to overlook that because of the distinctiveness of Ned and Grace and how other than the profession there aren't real life similarities to their counterparts (unlike the more blatant Viveca Scott-Arlene Dahl ones).
I know so little about football (during ANY year) that I wonder whether Eric Wagner was inspired by an actual heir to a football team, one who was criticized for paying too little attention to the game as opposed to "swinging" with the money. Maybe someone could answer that.