Seems like old times: Peter Marshall returns to Hollywood Squares (2002)

 After Henry Winkler's production company took over Hollywood Squares, the first order of business was retaining Tom Bergeron as host, though co-executive producer/center square Whoopi Goldberg had left. 

In December 2002, the series presented its first Game Show Week, with fellow MC's Jim Lange, Wink Martindale, Bob Eubanks, Chuck Woolery, and Peter Marshall, the series' original host, on the panel. For this particular installment, Bergeron & Marshall switched places, with Bergeron occupying the center square for the main game, then returning to his regular role for the bonus game.

Rod Roddy (The Price is Right, Disney's House of Mouse) served as announcer for the week. Carol Merrill (ex-Let's Make a Deal) flew in from Australia to lend a hand.

2 more similarly themed weeks would follow. Of course, Marshall had stayed in practice with some Squares-themed skits on In Living Color a few years earlier.