As I have been told. KWA is where KSC went to have their stuff made. Over time KWA grew and swallowed up it's parent.
The KWA H&K models have either non-existent, or wrong, or at worst Umarex butchery slapped on for trademarks.
The KSC ones are much more exact, proper markings on a magazine for example in a place where you don't see them when you employ the pistol.
Airsoft, where nothing is hurt but feelings.