Not sure how GBS, Dickens, Disraeli & Sherlock Holmes can be described as "famous guests".

Bob
Seeing the e mail was headed ´Simpsons´ prompted me to immediately respond with a reference to the last time I had my attention drawn to the place, thus -

Stuart Conquest, my invited guest when I played Millionaire?, may be seen on a video clip here at a ceremony at the restored grave of the great chess master Johannes Zukertort.
He died, as the attendant article explains, playing a game at Simpsons. http://www.chessvibes.com/reports/johannes-zukertorts-grave-rededicated-in-london

Was myself there many times in 1993 as the Short-Kasparov match took place in the adjacent Savoy.

You´ll have a pleasant evening!
Then I looked more closely at Bob´s e mail and saw that the Simpson´s site does indeed list Sherlock Holmes as a former illustrious patron!
That, naturally, sent me to check once more the details of Entry 142. Having done so I e mailed again -
Check out this example http://james-plasketts-coincidence-diary.blogspot.com.es/2006/03/141-giant-octopus-odds.html to see how curious your e mail and my response are.

Note the themes of Stuart Conquest, Sherlock Homes as a real life figure, Holmes coming to life, Dr Watson manifesting from Baker Street, Plaskett qua Sherlock, my wife´s poem and it´s reference to The Strand (the name of a magazine on which her father worked and in which the first Holmes story appeared and where of course Simpsons is situated) correspondence re cooperation on a project...
 
And not only was The Strand the name of the street in which Simpsons is situated but also, when her father worked for the magazine, he had visited an aging Sir Arthur Conan Doyle a few times. By the then the old gentleman was mainly into spiritualism.