Help ID this mag

[Mike B]

Greetings,
I young man approached my table at the Tulsa show and handed me an artillery Luger. I asked him what did he want to do with it. He said he wanted to sell it. After a few minutes of negotiating I purchased the Luger. My question for the forum is the mag. At first I thought it was a Swiss mag. But no Swiss cross or any other markings. Any comments or other information will be much appreciated.

Mike