From IMDB.com the 1976 cast considered was as followed...
"After the success of Robert Altman's Nashville, Vonnegut's novel was bought by producer Dino De Laurentiis for Altman. Altman's cast for the film included Peter Falk as Hoover, Alice Cooper as his son Bunny, Sterling Hayden as Kilgore Trout and Ruth Gordon as Eliot Rosewater (as Rosewater was to be portrayed as an old man, Altman thought it didn't matter that Gordon was a woman as he believed gender differences were not as strong in the elderly."
Much later this film came out in 1999 w/ a whole new cast.
Alice's part was now given to Lukas Haas as son George "Bunny" Hoover,
Bruce Willis as Hoover, Albert Finney as Kilgore Trout, Ken Hudson Campbell as Eliot Rosewater.
