The original mix is easy to spot because it will have John’s overdubbed “Roll up! Roll up! For the Magical Mystery Tour…” at the beginning of “Magical Mystery Tour” rather than the recording from the song. It also contains the original mono mixes of the songs.
My laserdisc, and 1997 MPI dvd also has John’s “roll up roll up”. I’m guessing the mono mixes of the songs is the only other difference to the soundtrack?
The original mono mix of “Magical Mystery Tour” was mixed on 4th May, 1967. This version, original had a clean introduction without the “Roll up, roll up” barker call. For the soundtrack version, the Beatles (John) overdubbed the “Roll up, roll up for the Magical Mystery Tour! Step right this way! Hurry, hurry, hurry!” that’s featured on the 1967 mono soundtrack.
Later, on November 7th, they re-recorded the same line, but dropped the “Hurry, hurry, hurry!” part. This November 7th recording (both mono and stereo) is we all know from the EP/album.
So, in 1967 we have two versions of the “roll up, roll up” line - the May 4th mono soundtrack recording that was featured on the TV special, and the EP/album version recorded on November 7th (without the “Hurry, hurry, hurry!” part).
In 1988, when the MMT was remixed for the Laserdisc and VHS release, the May 4th recording of “roll up, roll up” with the “Hurry, hurry, hurry!” at the end was added to a new stereo remix of the song.
As far as I’m aware, the MPI DVD uses the album’s stereo mixes (Nov 7th), but if that’s not the case, it will either by the 1967 mono soundtrack mix (if in mono) or the 1988 stereo remix (if in stereo).