Not so good news. Discs 5 and 6 are proving tricky. I've managed to rip the first 12 of 16 racks from Disc 5 and (so far) 20 of 22 from Disc 6.
The latter is still a rip in progress, but creeping along at a snail's pace. Disc 5 I tried several times, including on an old lapdog which has a CD drive, but no joy.
Ultimately it's only a very small number of tracks, but still quite annoying. Strange that the whole box (which arrived brand new and still sealed) appears to have 'difficult' discs, with all of them being incredibly noisy in my drive, even those that ripped easily.