>>507 All of this.
>>105 As Couch pointed out here, we know that Lex, cabbageanon and FakeAnon (as I shall call her) are the same person as all round Twitter and fandom favourite Firenbrenie. She initially insisted she wasn't but she's stopped denying it now. At >>297ff I described firenbrenie's Twitter description as hers and she didn't demur.
And, as I pointed out at >>322, Firenbrenie lives and works in - drumroll please - Tblisi (from her Twitter before she locked it). Which is in Georgia (the one which was formerly part of the USSR). I too spent a lot of my time studying inflected languages and FakeAnon's use of English is entirely consistent with Russian or one of its relatives being her first language - and, I'd venture, with it being the language she speaks first every day. Immersion doesn't eradicate all traces, but it softens the edges. In short, Lex wasn't born and raised in London, and she doesn't live there now. The yellow pages reference bears this out - I didn't pick up on that. Good spot. You are right - it is to any British person the large yellow phone book with adverts for plumbers and such.
The interesting thing is that you don't need a degree in linguistics to work this out; it gives itself away to any native speaker, especially when there is (to put it mildly) a lot of comparative material available. A lot of people have told the tea girls on tumblr they think the crazy letter to Toby came from firenbrenie: http://teatime-with-sabrina-and-violet.tumblr.com/post/134349458611/the-letter-posted-at-tobys-or-not-posted-just
I'll just leave one final thought for our resident troll, courtesy of another Toby (the one in The West Wing): "When even the internet doesn't want a piece of this, you have to ask yourself, how far from the pack have you strayed?"