As dmg said, the Glasgow NHB show was not broadcast "live" while the performance was actually taking place but was recorded and an edited version was broadcast. I have a feeling that, at one time, Radio Clyde was broadcast to a wider area than at present but I'm not sure. I certainly did not record the broadcast myself but got it from a contact (I forget from whom) and the recording was OK but my contact was not perfectly tuned in to the station. It may be that he was on the edge of the broadcast range.
The more technical people on this site may comment and may contradict me but I doubt that it is a recording from the soundboard. More likely, Radio Clyde recorded it themselves. Settings for the sound that the band would want for that particular venue would be different from the settings required for a broadcast, I would have thought. Am I wrong?
I am pleased that the Lockerbie recording has been enjoyed by others. The venue being a former cinema not usually used for live gigs, there was no dressing room. I seem to recall that they used some kind of small hall next door, requiring them to go outside to go inside, as it were. I have a vague memory of photographs taken of the band in the passageway between the two - but it was a long time ago.
As for those cassettes, not much would be of direct interest here, I suspect, but there are many radio shows about all manner of musicians, performers and others. I did record Brendan Croker in 1993, with his permission, at The Bridge Hotel in Newcastle, which very close to those steps in one of MK's songs.