When it comes to AK mags, it gets interesting. Basically, if the magazine stopped production before 1994 or whenever that ban happened, it's good to go.
here's a short list as to what is concretely pre-ban:
east german mags of any flavor (7.62, or 5.45, steel, or bakelite) since East Germany shut down when communism fell.
Russian Bakelites- the russians stopped using bakelite sometime in the 1980's in favor of polymer mags
Russian aluminum mags
Russian slab side mags
Russian waffle mags
Russian Molot (moscow metallurgical plant) stamped mags (plant shut down mag making when they privatized, I believe)
The rest is purely up for speculation. I think the bulgarian mags that are painted Izhevsk polymer mags with their factory proof ground off are possibly pre-ban: it's speculated that all bulgy mags were this way until they set up their plant's molding equipment- refurbed russian magazines.
There were tons of romanian AK mags in the country before the ban. There were also tons of bulgarian mags, too (5.45x39). You see these sold at every gun show as pre-ban. But there is absolutely no way to tell if they are or not.
Someone chime in, but are chinese mags pre-ban? Was there a halt to their importation or are they still pumping across the border?