I think that rivalry (Luton) kicked off, literally, in 1969. They were top of Div.3 and the game at the Goldstone was a big grudge match. Didn't Luton's supporters club hut get torched in the return match?
Well if there were 300 of them and 29,100 of us it's not surprising that you didn't see any on the train. I did have a chat with three Burton fans in the WSL bar after the game, very pleasant.