Originally Posted by zollen
What's the difficulty? Any info?
If a gun is the same brand as the gun, it is pretty much guaranteed to fit, since it is the same brand made for the guns. However, different brands might make their pieces a bit bigger or smaller, which in some cases require some modification.
Also, if you're looking for some cheap-ish parts, international dealers are sometimes cheaper. However, they come at a cost (no pun intended) because of shipping rates, times and customs.