Very nice specimen of the "M"! I wish mine still looked that pristine. But it still goes bang when requested.
As a side note, OCD-type question...I see 2 witness holes on the back of the magazine, there may be a third? Is the Polytech magazine the only Chinese AK magazine with multiple (3) witness holes as compared to the (1) that the rest have? I guess this would be a question for jliu123. Did you outfit your "M" with a Polytech magazine?
I've not had a chance to see the new Korean-made flatback AK magazines that came over a year or so ago. It may be one of those?
Gotta love the "M". Especially one that's been preserved so well. Thanks for sharing.