What Kind of Luger is This

[icemanjim]

I am trying to figure out what I have here. The story is that it came back from WWII. As you can see in the pictures it has no date stamp, it is manufacture, has no markings on the handle and a 5" or 6" barrel depends if you measure to the chamber. I believe it to be a Navy Military but not sure. If anyone can help it would be much appreciated