What Luger is this?

Hello,


My uncle asked me about a luger he recently purchased. Unfortunately, I am pretty ignornant about the variations, can anyone suggest anything? This thing has a 3 and 1/8 " barrel, is 9mm, has the number 665 stamped on it and the clip which has an aluminum bottom and the silhouette of the front view of a tri-plane on the frame. It also has the number 83 stamped below the air plane silhouette. Inside there are a 7 and a capitol O. It came with a shoulder holster and the man from whom I bought it said that it was a

German aviator's pistol.


Thanks

Simon