Wood Bottom Mag Help

[sdmark777]

I was rummaging through some old boxes of gun/Luger stuff. I ran across this wood bottom magazine that I got well over 30 years ago and I can't remember where, who from or how I got it. It has a serial number 74?7 which has been stamped over with GERMANY. It also has the plus. So I would like to know what the most likely scenario is. Is it a first war DWM military issue extra magazine that was exported in the 1920's as an individual magazine, so they stamped GERMANY on it? Only one I have ever seen like this. What do you guys think?