I've read reports that the AC3 track on the Die Hard laserdisc is an accurate representation of the theatrical 70mm Dolby 6-track mix (as is the case for Alien). There's this post on alt.video laserdisc that mentions that the surround channel is mono (matching the 6-track's 4.2 configuration) and also some posts on forum.lddb.com and avsforum.com about the panning of certain effects. (However, these posts are from our eccentric jedi friend who ignores everyone, so I'm not sure how reliable this info is.)