It would have been different from the restored version. Said version was missing scenes and assorted things that could not be put in place by simple editing to create a post facto restoration. The 1998 version is closer, and is as close as you will ever get, but it's not exactly what would have been given the rough cut is gone.
The question here is something I always come back to in alternate history, which is before asking what if something happened, asking if it could have happened. How do you get the Studio not to interfere and/or to listen to Welles? One thing I do know is that Charlton Heston, when told they wanted to bring him in to shoot some scenes behind Welles' back for the studio manipulated version, initially refused and said that if Welles wasn't coming back, then neither was he. I believe the reason he relented was because he was legally required to do those by his contract. Didn't Welles also run off at some point after finishing, when staying there would have meant he could have prevented what happened with the studio reedit and new scenes? Maybe I'm misremembering.