Sorry to bring this back from the dead but I thought I'd give my two cents. I've had a GP 1975 for about a year and a half. Did the usual inspection that anyone should do when getting a century gun, or at least I thought I did.
Issues with the gun: when I first got it, it shot low, so I bought a site adjustment tool and problem fixed. Then after about five hundred rounds, the roll pin holding the gas piston came out, so I bought a new pin and installed it my self and the problem fixed. Since then, I've shot about 3000 rounds through it with only one malfunction (due to cheap after market mag). No other issues.
In summary, Century is not the best built AK but there an AK non the less, and most issues with the gun can be fixed yourself. And if you get spare mags, only get army surplus mags.