Watch for premature excessive wear on the locking lugs on the bolt. Also watch for wear in the channel on the bolt carrier that the lug from the bolt rides in. Also look for excessive wear on the bolt carrier tail where it strike the hammer on its backward stroke. If a Tapco G2 FCG is in the rifle, it will probably beat the tail on the bolt carrier up pretty badly. It probably has something to do with improper heat treating, but I'm no expert on the subject. Hopefully you'll be lucky and get one of the good ones.
I'm Darwin... I think I'm just going to pass on the century and the AK all together for awhile. The whole reason I wanted the Century C39V2 was the quality feel of the milled receiver and with the magpul furniture it felt so solid and really nice... after reading so many posts about the BCG and all I think I'll pass... My AR15's, Mini' and other rifles will do me fine for now.
Arsenal Feels cheep in my hands but supposedly good quality, but expensive
Century, Feels QUALITY in my hands but has issues, mid priced...