Here's some info on tracks that you can actually purchase either from Japan, or the Official Queen shop:
The following tracks were restored to some degree for the 2004 remaster of Greatest Karaoke Hits:
Somebody To Love (4:57) (restored ending but fades to barely audible during final piano notes)
Tie Your Mother Down (3:42) (restored intro)
Another One Bites The Dust (3:33) (reverb ending restored)
Keep Yourself Alive (3:34) (restored intro, still fades early)
Under Pressure (4:01) (restored ending, originally just had one snap at the end)
It's A Hard Life (4:09) (restored ending, originally just had one piano note at the end)
Friends Will Be Friends (4:11) (new version, no longer has video ending with crowd)
And it should be noted that the karaoke of One Vision runs 5 seconds long (4:07) due to originally being pitched slower for the video, and this has not been corrected on the new version.
Greatest Karaoke Hits at the Queen shop: http://www.shop.queenonline.com/mall/productpage.cfm/qen/500165/52128
Toshiba/EMI TOCP67422 (Copy controlled 2 CD set)
I had no trouble ripping all of the tracks from my copy.