A friend has a rather nice collection of memorabillia that a elderly lady left to his wife.
It has letters from the old lady's boy friend when stationed in Gibraltar and possibly the most interesting is a spy camera that fits into a matchbox.

I looked the camera up years ago and found that Germanicon tourists visiting countries that the Nazis had designs on were given these little cameras and instructed to take photos of anything that might be of interest without drawing attention to what they were doing.
I suspect the young soldier had taken the tiny camera from a tourist who got too close to something of importance.

I'll see if I can get some photos of the collection and the camera.