31152 & 31236 South Moreton 29 May 1982

31152 & 31236 pass South Moreton on 29 May 1982 with an unidentified westbound working. Terrible high overhead backlighting, but I haven't got many pictures of pairs of Class 31s working a passenger train, except of course for railtours. All the usual information sources have failed to provide any information on this train, so any information would be gratefully received.