I did a bunch of publicity videos for this - There wont be much of the original footage in the wild yet as it was in the vault until not long ago.
Most of the audio is from mono 1/4 tape running at 15 ips used by the film crew with some of it on 8 track from the studio.
There was 4x the audio as they just left the recorders running over the 22 days they were shooting - cameras were on/off a lot
In plenty of places conversations were drowned out by cranked up amps ( on purpose and unintentionally ) - the Sound dept wrote ML software to split out everything, so much of it, especially the intimate conversations were not at all audible originally. There is a video showing comparison but not sure where this is available, it was shown to a bunch of press
It's an pretty amazing watch hey