Highly odd, seeing as the barrels are new from Green Mountain to meet 922r and barrel length. Odder still since the OEM barrels are chrome lined & generally in good shape, along with the other kit parts. Century's been known to forget barrel pins before in AKs, sounds like that was what happened. Century never tabbed many bolts, seeing as CP sued them for patent infringement (yes, that obvious solution was granted a patent somehow).
As far as finish, there's no lower to match an upper, so I'm not sure what you're describing.
The VZ2008s have a reputation as one of Century's more reliable builds, because they didn't actually build it; Century monkeys don't do mill work. All they did is assembly and apart from the usual sight base & barrel pin incompetence, the gun is hard to screw up. Neither is particularly hard to remedy. Gun finish is ugly, corners are sharper, stock is really stiff, carrier is untabbed, and the OEM parts are more worn than the CPs; that's really the only difference (oh, and many of the barrels are 308 instead of 312, but it hasn't been much of an issue since x39 doesn't operate on the ragged edge)
TCB