159011 Andover 15 May 1994

159011 leads an unidentified classmate out of Andover station on Sunday 15 May 1994. Even after extensive research, I have been unable to identity this working. It is not, as you might suppose, an ordinary Network SouthEast passenger working. The Exeter train had departed half an hour earlier, and nothing else was due. Clearly some kind of special working, which is confirmed by 'Special' being displayed in the destination blind. However, due to the general lack of reporting of anything that isn't loco hauled, I can find no record of this. Information anyone?