Just read through some of the 1989 script. It's amazing that this script was from May 1989 and the film was completed and released by December of 1990, just 1.5 years later. It underwent a lot of changes during that time.

That said, it's still very much like the version we got. Obviously, Tom Hagen was not in it and they changed Willie Cicci to Joey Zasa. The Immobliare deal is still in there as well as the church stuff.

I think that this version with some minor dialog changes would have been a little better, but overall, it's still very similar to the one we got.

So suffice to say, the casting hurt the movie the most, not the script. Had they not gone with Hamilton and Sofia Coppola, Part III would have been much, much better.

And as much as I would have loved to see Hagen back in the movie, from the script it doesn't sound like they had much for him to do.

One thing I feel strongly about is Michael dying at the end. It felt much more tragic with Mary getting it instead of Michael and then Michael regretting his life until he died.

I do like Mike's funeral juxtaposed against the killings though. That would have been different and better than the opera scene.