One of the shops in Denmark Street (which, for you US users, is London’s answer to NYC’s 48th st.) has a large range of vintage Electro Harmonix pedals in stock. Can’t remember the name, but if you go down there, you will see them in the window.
You could also try eBay. I’ve recently bought a Clone Theory from someone in the US. Once you’ve added shipping and a 110v transformer, the cost starts to creep up though…