The Dark Knight Returns as a film in the 80s

[BH/HHH]

Had they made a live action film of the Dark Knight Returns in the 1980s in sure that Clint Eastwood would have been cast as Batman (had he been wiling) and even David Bowie as the Joker but who else do you think old have been cast on this film in the 80s? When I think I really can't think of anyone who could have portrayed Superman outside of Christopher Reeve.