Jonno, thanks for the file; I don't think this could be useful for upscaling, as, AFAIK, the original file was encoded in mp4 or Sorenson3, so upscale a 2nd generation lossy video is not a good idea... I think I'll stick with my version - yet not perfect, but watchable.

About 5.1: I'm sure someone has recreated the audio from the 2.0 soundtrack, and I've contacted a person that maybe could have that 5.1 audio... I'll post here if I'll receive it.

UPDATES:

here you are the latest trailers found or converted:

THX (unofficial) - Star Wars (upscaled to HD)
THX - BROADWAY - LASERDISC - NTSC PCM
THX - CIMARRON - LASERDISC - NTSC DTS
THX - Speaker Array
THX - Lincoln Car Audio Demo
DOLBY - Dolby Atmos Theatrical Trailer
Other - DATASAT Digital Entertainment

soon I'll update first post adding the following and dividing trailers in categories.