I read the novel during my teens, when I was devouring any spy literature I could get my hands on, and while I'm sure it was better than Adam Diment's The Bang Bang Birds I couldn't remember much beyond the vacuum cleaners and the checkers game.
I suspected it would make for an entertaining play, though, and I was right. The cast of four covered all minor parts between them, with much dashing off and on in a different hat, jacket or gender, and lots of amusing business to simulate cars, planes and lavatories. In order to preserve Graham Greene's best writing, the actors took it in turns to freeze, drop their ludicrous Latin American accents and narrate a paragraph or two to move the plot along.
Like the original, things started off light and frothy but built up to an atmosphere of menace and suspense - so successfully that I was on the edge of my seat when the curtain fell for the interval and couldn't wait for the action to start up again. There were rather more cross-dressing nuns than I remember from the book, but you can't have too many of those. Oh, and a clumsy crack about Weapons of Mass Destruction which got no laughs whatsoever.
Now, whatever have I seen Clive Francis in to make his name and face so familiar? I'm damn sure I've never knowingly watched The 10%ers or May to December.
PS: Ironically, now Russia really does have a vacuum bomb.