Spitalfields market record fair (once or twice a month. don't know exactly when) http://spitalfieldslife.com/2010/12/07/ ... talfields/
And don't forget to ask in stores what they have behind the counter. Usually the more expensive/rare items. Like with haggle. They have all the 7 inches behind in boxes arranged on price ( records less than 10 pound box, 10 to 20 box, 30 and up etc) , so you have to ask for it.
Meastro records peckham. found 2 copies of Arema - back a yard 12 " there not long ago.