I was going to suggest the fruitcake as well.
Here are some ideas from both of our weddings (one in the US, one in the UK) We made sure to serve tea as well as coffee, since my family thinks TEA when they think of England. As for you, make sure you wear a horseshoe somewhere on your body. We made sure to play typically English songs a lot as well... the Beatles and Stones mostly... And in my English wedding I wore a sixpence in my shoe... (something old, something new, something borrowed, something blue, silver sixpence in your shoe!)... and are you doing a wedding program? If you are, you could explain the different cultures traditions in it.