It sounds like the tape archive is in a bit of a state if a pre-final mix remains logged as the master and master tapes are missing! No surprise given the nature of the band's recording career but it's a bit of a shame. No criticism of you, Jeremy, it sounds as though you had to put a massive amount of work into this and it isn't any surprise that an oddity or two slipped through the net. It's interesting to know that it wasn't a conscious decision to use a different mix. Presumably the "new" mix will be the one to feature on the vinyl edition?