Take a look at The Lavendar Hill Mob (http://www.imdb.com/title/tt0044829/plotsummary) or even better, The Ladykillers (http://www.imdb.com/title/tt0048281/plotsummary), both of them archetypal "criminal plot goes wrong in darkly humorous ways" films. And with Sir Alec Guinness, pre-title. Both of them were re-made recently, with well-deserved lack-of-success.