Went into MINT in Covent Garden the other day to see if I could get any more nice 70's retro cycling tops (bought a lovely Bianchi Faema one in there in Sept) but couldn't see any.
Got chatting to the owner, James, and turns out he's got them all 'under the counter' so bought another one. James said that anyone who comes in with an Addiscombe membership card can get a discount, from £25 down to £18. Some nice tops in there, though some are very 'snug'.
He's also got a couple of lovely fixed's in there that he had built by Paul at Kiwi Cycles... http://www.kiwicycles.com/soldbikesii.htm (scroll down for James' lovely white Harry Hall).
Definately worth a visit in your in town.
http://www.mintvintage.co.uk/about.html (Note the skylight 'installation').