It's not an unreleased recording at all. B-sides from The Boy Racer singles were taken from this gig. It was broadcast on the BBC and Westwood One in America. It's among the most bootlegged Morrissey gigs as it was pressed many times on bootleged CDs in the 90s. Although both the BBC and Westwood One airings played different songs in a different order, BBC international offered 14 tracks, in the correct order, but missing the last two (like all the others). The BBC International CD I have is undoubtedly the same version they are releasing here.
Morrisssey was also struggling through a cold for this gig and you can hear it in his voice, he sounds very off vocally. Any other show from the Boxers tour would have been preferable.
I lack the intelligence and command of vocabulary to reply to you. See above.