The Stephen Sondheim references may have more significance than just the fact that Angela Lansbury had starred in his "Sweeney Todd" more than a decade earlier. He actually had a new hit show in London the year this episode was first broadcast - "Assassins."
Although set in London, UK, this episode was filmed entirely in Hollywood, with library stock shots of London inserted to add authenticity.
There are multiple references to Jessica going to see "the new Sondheim musical." Angela Lansbury starred in the Stephen Sondheim musical "Sweeney Todd" on Broadway.
Per the title, the expression is part of an English counting game. "Tinker, Tailor, Soldier, Sailor, Rich Man, Poor Man, Beggar Man, Thief."
Trevor Eve and Sharon Maughan are married in real life, but they share only scene together.