It is a little bit difficult to tell for sure, but it appears that there is a detent in the right side of the stock lug for the early push-button stock. I have recorded 5 other Lugers in the early 10000 range, all lower than 10010 and none with the B suffix. These pieces do have the push-button stock detent in the stock lug. A good clear photo of the right side of the stock lug would be helpful. I would not expect a GL on this series of Luger, but I also would not expect a B suffix.
It also looks like the magazine is of the early flat-button type, but I would not expect this Luger to have an unrelieved frame. Also, the punch crimp at the top of the magazine appears rectangular rather than "D" shaped and the checkering on the button is fairly coarse, which is not usually typical of a DWM produced magazine. A real odd item. A photo of the bottom of the grip with the magazine removed would also be appreciated.
