Hmmm...be careful - Kow Yokoyama is very protective of his copyright.
This. It's not just Yokoyama: Japanese hobby culture in general takes IP a lot more seriously than western hobby culture. It's not like, say, Star Trek, where you can get away with unofficial models if you keep your margins low, and the fans will be on your side. With a Japanese IP, the fan community itself will turn you in if they think you're operating without licencing.
And with Ma.K in particular this culture has carried over into the western fandom, so if your friend who's making these for sale isn't licenced to do so, he's golfing in a thunderstorm.
