Annie Mole's blog clearly states that it looks like this:
Unfortunately I decided on the basis of Wikipedia's details of the '63' route (which is run by London Central and goes past the station) and the file name including 'EC' that it was indeed Elephant and Castle.
Further digging in the '63' Wikipedia article says that the route only uses 'deckers anyway, and the picture on E&C station wikipedia article kinda gives it away.
The bus did look a bit fishy; no lights and no driver, Did you remove its destination - I seem to remember that London buses display destinations even when powered down, unlike everywhere else where they use LED's.
I'll openly admit that I have very limited knowledge about London, I've been there perhaps a dozen times, my total tube mileage is definitely only in double figures.
The other answer I nearly gave was Uxbridge; I know that has a wide entrance between shops, the 'Centralness' of the bus put me off that one though.
If it were a building in Sheffield I'd probably know fairly quickly...
