How? Where?? Do any of them function?
They can be find all over Normandy, in other parts of France and generally anywhere in Europe since it was such a large battlefield.
Not all are found in the ground, that's why some are in better shape.
I assume they don't work (again they are not mine)
Some might work, like a gun found right after the war and kept inside a family from generation to generation.
Heck some people still find tanks in old barns.