Let me tell you a story. It has nothing directly to do with MK or DS but may throw some light on all this.
It was many years ago and I forget some of the details and maybe the exact chronology but it went something like this. I was looking to get mrs twm any unusual item for her birthday and was asking around at the local record fair. One of the dealers said he had something of interest but it was in Newcastle. I said I'd come across some time and, soon, an arrangement was made. I took my elder son with me and, for some reason that I disremember, I wanted to go the terminal building at Newcastle Airport on the way. There, my son noticed one of his favourite bands checking in. They had played in Newcastle, at a fairly small venue, the night before and he managed to get some autographs. Off we went into town and I got the item I was after. We mentioned seeing this band at the airport and this guy said he had recorded the show. My son was interested in getting a copy but the dealer was reluctant. He asked what my son had in exchange and I reminded my son that he had made a decent recording of a Dylan show in Glasgow (another story in itself) and they agreed to exchange cassette recordings. The guy said he recorded just about anyone and everyone who was performing in Newcastle. Later, I got a call from a friend saying they'd bought a Dylan bootleg LP and they could hear my son's voice on it asking the time. He was checking, so that he turned the cassette at the right time. Anyway, I tackled this dealer the next time I saw him. He gave me a few copies of the bootleg, saying that he exchanged cassette recordings with another contact who sometimes had bootleg LPs made and that's what had happened. This was, I think, in 1990, close enough in time to the concert you're talking about.
Just a thought!