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.... but I DO happen to know...

Back alley behind No. 10 Downing Street?

Close but not getting (Churchill's) cigar.
Only five miles out.
They say it's around here:

Your powers of deduction and observation never cease to amaze me.

Much has changed since that picture was taken and the 2 story buildings in the background are likely to have been torn down for lack of efficiency. Thanks for letting me know.