Hello Group.
I just found a spare mag when sorting through a drawer with pens, pencils, notepads, etc. (well I guess that's about right - it is a magazine ?

)
Blued body, plastic bottom, no markings at all except mauser logo on the spine. Pics attached.
I have a couple of questions.
Is it anything special/unusual, possible vintage?
Would it be suitable for shooting in 1917 DWM? My other mag won't operate the hold open, and the spring in this one already left a strong impression (in my thumb.)
Thanks,
Fritz.