Doesn't look like anything unusual with regard to the magazines. Police pistols are occasionaly seen with two matching magazines, which this one appears to have. Too bad someone ruined what was likely a nice police luger.
On the link to the pistol I’ve posted, the inserted magazine in the photos doesn’t sit properly. It looks almost backwards, even if not fully seated the angles of the magazine base look wrong. Perhaps its me.
Nothing wrong with the aluminum bottom magazine. In late 1939 a new magazine design came into use that used a zig-zag elongated magazine spring rather than a round shaped coil spring. The front edge of the magazine body bottom was cut at 90 degree angle to accommodate this new spring.
Once you see it as you have here, it will probably jump out more for you when you see them in the guns. Look for photos of post 1939 Lugers with matching mags or better still look at any magazine in the Luger with the visible pin going through the bottom piece grasping knob. Any period black bottom magazine will be made the same way.
