No. 10 DOWNING STREET: Yesterday, I got a special tour of 10 Downing Street, courtesy of my friend Helen, who is a member of the No. 10 staff. Fun fact: Prime ministers, Margaret Thatcher among them, leave their mark on the building in curious ways. Above one of the interior doors is decorative molding with swirls and curls. At the end is the tiny image of a “thatcher” on a ladder carrying thatch for a roof.  Cool.  (Thank you, Helen!)