I'm no fan of Alec Guinness. He always seems to come across as slightly smug and superior, and his role in this movie is no exception.
However, there is so much to enjoy from the rest of the cast, the barmy plot, the direction and the script that I can set that aside.
Guinness is in a restaurant in South America, showing off his wealth and relating how he came by it to his dinner guest. As the bank clerk who accompanies gold bullion deliveries, he was able to plan the "perfect robbery", but the execution...well, with the likes of Alfie Bass, Sid James and Stanley Holloway as partners in crime, you might expect that there would be problems.