I was there, remember it well. The last 30,000 plus crowd in Hull and the last one at Boothferry Park. Don't recall ever doubting City would beat WHU either on the day before or during the game.
Gates before and after WHU were both 9,000 (PNE & Millwall) This was when Hull and Rovers combined couldn't fill the Costello Stadium. Massive floating support, the magic of the cup, decent away following for the Hammers? Whatever. we gained then lost over 20.000 'fans' within a month.
Don't recall WHU bringing that many. One football special direct to the ground if my memory serves me well. Don't recall any Hull Iron flags either. The terrace antics do get a mention in one of Cass Pennants hooligan books. Seemingly they didn't expect the welcome committee that they received.
I have a vague recollection of a load of their fans walking from town to Boothferry Park along one side of Anlaby road, with City fans on the other side. Possibly one of the first sightings of stereotypical skinheads, polished docs, too short white jeans and braces.