I've recently found a Working Timetable for 1984-1985 and there was a service from Mayfield which stood out as being a bit odd. There's a listing for a 3O12 service in the heading from Manchester Mayfield at 00:00 to Crawley, but the timetable only seems to show times from Manchester Piccadilly at 00:15. There doesn't seem to be a listing showing it shunting from Mayfield to Piccadilly in the opposite (Down) timetable direction.
Does anyone know how this service would have operated?