There was a full winter season where the scheduled AirUK early morning LGW-EDI-GLA-LGW circular flight was operated by an Air UK Leisure 737 (which I think was a -400 by then) before it set off to the Canaries or wherever at about 1100.
Going back to an earlier topic, I've checked the schedule books for NCL for 1985 and 1988 and can find no record of BA operating IT charters overnight from there - which was what I thought. They were doing this from MAN, GLA, BFS and to a lesser extent EDI but there were no regular BA charters shown ex NCL. In 1985, the NCL-LHR service was a 737-200 on the Newcastle nightstop and a mix of 737-200s and 1-11-500s plus a Trident 3 each afternoon. By 1988 it was a 757 on the nightstop and evening up & back (where the Trident 3 used to be) and still 737-200s and 1-11-500s on the rest. Newcastle was one of the few (only?0 BA domestic destinations to regularly see the A320s and also the four 737-300s which BA leased from Maersk for a couple of years around 1990-1992.