|Perhaps a coat of paint?|
I suppose it's almost an urban legend to people in the Northfields area of Ealing, I think that ever since I've been living around here (on and off for over 30 years) it's looked the same and it is a bit of a waste when London property is at such a premium.
If we go back to November 2008 the story seemed to go something like this (from West Ealing Neighbours site)...
"Apparently, the couple who own and live above it used to argue a lot about the café and haven't spoken to one another for 20 years or more.
Indeed, one of the those who posts is 49 old and says it's been closed ever since she was a child. I must admit we've lived here for 30 years and I can't ever remember it being open. I guess nothing will happen until one of them dies or they move away - all very odd."
and from a 2007 posting at Brentford TW8 site Maggi Howells notes
"Next to the SAAB garage on Northfileds Avenue; I have lived here since 1976 and it has never had any customers!"
The nature of the state of the building has been questioned here and there's someone who has taken more of a look here.
It would make an interesting study/film (fact or fiction)