I believe Norincos improved their quality in the past few years compared to the earlier models. My brother told me about a Philippine forum where some know it all seems to claim otherwise. This guy sells a fabricated magwell which he claims to fit the Charles Daly and SAM frames (both from the Philippines too) yet has a shoddy fit on the Norks. Here's a link.
The language is a bit hard to comprehend. The poster seems to blame the Nork frame than his backyard manufactured magwell. He claims that shooters should be aware of the problem despite the obvious flaw in the photographs. The nerve of this guy. You be the judge.