A bit of a side project here, but hopefully an interesting one!
It appears that the theatrical 5.1 mix for Terminator 2 was briefly available on the first issue R1 DVD (which wasn't around long before the marvellous special edition came along). See the second post here (from the very knowledgeable Disclord): http://forum.lddb.com/viewtopic.php?f=12&t=1409
Since I was assembling a disc that included the theatrical cut of the film, I thought I'd look at syncing that mix to BD video. This involved using Womble, a rather blunt tool for such a job, but it meant that I could nip'n'tuck the track without reencoding. The result is a 5.1 AC-3 which matches the theatrical cut as found on the Skynet BD - not the greatest source for video, but by far the most common source for that cut.
I haven't studied the track for all of its differences with the later Rydstrom mix, but it certainly has a different feel. PM me if you'd like to try it out.