Well I'm a little confused. Capitol and Mercury are now part of Universal and no quad masters are available, yet back in the day DTS were able to locate quad masters of 2 McCartney discs, Steve Miller and BTO, all on Capitol and Mercury. So it would seem that some quad masters are available.
The Universal Fire was in 2008, the DTS Music Discs came out in 1997. Things can change over a decade.
Check Richard Carpenter's comments about the Fire and the Carpenters masters going up in flames at 23:00 on the interview.
http://deadline.com/2008/06/update-universal-fire-burns-music-history-5937/
http://thedownloadshow.podbean.com/2014/01/20/richard-carpenter-interview/
http://forums.stevehoffman.tv/threads/richard-carpenter-interview.340781/