"original MK-012 microphones produced by OAO Oktava earlier can also be labelled Oktava ?C 012." (op.cit.)
I believe the "?" character is actually a Cyrillic (Russian) letter which is not represented in this character set.
But the photos on that page are an excelent visual guide to distinguishing between the genuine Russian product and the knock-off Chinese mics.
The Oktava mics sold by Guitar Center were generally run-of-the-mill output from the Russian factory and you had a good chance of getting a lemon. While other vendors such as The Sound Room (www.oktava.com) and later www.oktavausa.com perform the extra layer of quality control required to ensure a quality product and to offer such services as matching stereo pairs of capsules, etc.