This is because the PAL VHS audio source used for his release has been sped up from the original 24fps film but they (the VHS producers) didn't just resample it they also preserved the audio pitch
Really? I've never seen (heard) a PAL release with preserved pitch. I've only recently seen it used on UK broadcasts of Stargate, and you can tell it's had something done to it because the sound warbles and clicks.
Have you tried to align the audio track to the video yet? Because I'd imagine you'd be unlikely to get a perfect 25fps from your VHS player. I remember, for some reason, my friend and I pressing play at the same time on our VHS copies of Star Wars and after only a few minutes they were a few seconds out of sync.
I don't think you can ever time stretch/compress perfectly - if the tools you've tried haven't worked, have you considered that a combination of tape stretch and your player's mechanics could have conspired to lower the pitch to something similar to the true soundtrack?
DE