This is a film I've been waiting to see for years. I even own a poster of it but it's never been available in any format I could watch till now. It's a nicely done 1960s caper comedy with Michael Caine and Shirley MacLaine and a very good performance by Herbert Lom, not playing the buffoon. The twists are good without going over the top, like so many caper films do nowadays, but really this is a film about a certain time and a certain place, the imaginary world of 1960s jewel thieves, and crepe-soled shoes, and well-cut suits, and cocktails, and a penthouse apartment that opens up to a rooftop helicopter pad. What elevated this particular movie was the direction of Ronald Neame--the lighting and camerawork are beautiful, and while it feels very much a studio picture, despite its location-hopping, it doesn't matter when the set design is so beautiful.
I know this is a particular favorite of Quentin Tarantino's, and there is an early scene set in a Hong Kong bar which was clearly part of the inspiration for The House of Blue Leaves in Kill Bill.