As for audio files for LaserDisc audio mixes, our member–schorman13–made an archive where he ripped audio tracks–AC3 bitstream, digital and analogue stereo tracks–from all the LaserDisc releases and uploaded them. They are on the usual place.

You can read about it here:
http://originaltrilogy.com/topic/Star-Wars-Laser-Disc-Audio-Archive/id/14542

Mind you, these audio files are not Blu-Disc ready, so, if you are making discs of these, you are going to have do the work in:

Upsampling them from 44.1kHz to 48kHz
Sync’ing these tracks to what ever version of the video you like