There has been some discussion here as to how the audio should be handeled. I'm a professional audio engineer, and even though I work in music production I'd like to share my thoughts on the video issue with you guys.

In terms of handeling a speed-up (or speed-down in this case) it seems to be an industry standard in authoring that pitch-shifting is actually never applied as it's degrading sonic quality, even the best algos do, with only a few exceptions like for instance the "Lord of the Rings" PAL discs. Since the source in this case is a laserdisc you can be sure that in 1997 they didn't use time-strechting/pitch-shifting back then, they use either resampling or much more likely some analog conversion.

Now, it works like this: Never time-stretch or compress, only resample. If your source is a PAL disc that has been sped up from an NTSC source the audio is already 4,27% faster and therefor higher in pitch.

25 fps : 48000 Hz = (24000/1001) fps : x Hz --> x = (48000*(24000/1001))/25 ~ 46033,966 Hz

Now, at first you need to merely SET the sample rate of the 48000 Hz audio file to 46033,966 and afterwards convert the samplerate back to 48000 Hz. The loss of sonic quality is limited to some upper highs which arguably only audible to infants and dogs anyway. Pretty straight forward.

EDIT: Alright, I just noticed that this project is 3 years old. Anyway, this is how it should have been handled. ;)