MWCLASSIC.COM This is not really a shop, it's a web site! They do tolerate visitors but not too many as they are based in an industrial unit at the junction of Essex Road and Balls Pond Road.
They are VERY knowledgable, and stock everything from rare brass lenses to Hasselblad SWC's to Leica. There must be 40+ years of experience between the two founders who also buy and sell gold and silver coins and vintage watches.
Their website is updated every friday evening and many customers and dealers alike have their respective fingers on their computers F5 (Refresh) key to be the first to grab the bargains.
Many other dealers from both UK and overseas buy from them and they are very good value for money.