OK the good news is @BenAkenobi 's copy is correctly mastered. I've pulled together some scrappy draft notes and stuff here http://jmtd.net/quake/ - but in short, the freq analysis of the beginning of track 2 (first audio track) is identical between Ben's copy and a rip of mine with cdparanoia, which is a pre-empt-aware ripper (so it did de-emphasis on the cd audio after ripping).

I have a graph of a bad rip I can put up (which doesn't account for the preemph flag), plus some accuraterip checksums, more details about how various rippers handle etc. - I also want to overlay the freq analysis of a good and bad rip to highlight the difference.