If they can make Ashlee Simpson sound like she's singing in perfect pitch, I'm sure they can do something here.
No seriously, I'm more familiar with the music industry than film, and I know there's a tremendous amount of digital 'fixing' you can do with old recordings. On a couple recent Thin Lizzy reissues from the 70's, they were able to re-tune the guitar parts on a few solos to put them into proper tune. They weren't out all that much originally, but while they were remastering & remixing the tracks they decided to 'fix' them. Even if you're not remixing and just remastering an existing 2 track master, you can work with individual frequencies to bring out instruments that were barely audible in the original releases, so I'm sure something like this would be possible unless there's something extremely unique about the technology used.