I have several AK mags with a quater moon stamped on the rib. Does anybody know the country of origin? I also have one that has a serial number stamped near the bottom. The blue color is much deeper than on others. It has numerious proofs like a "5" in a triangleo ne the rib, "S7" stamped on the body near the bottom on both sides,  a "2 T" in a circle on the rib and a number 6 or 9 on the rib. Any ideas?

Are there any websites showing all the proofs marks so you can know the country of origin?
Thanks in advance,
Jon