Dear Michael Kotzulla, don’t buy all before we know whether it’s really gunawani (or something else very interesting. It it still possible that the fish are some of the regularly imported bintan-variants. But to buy a few males and females would surely be a good idea.
Perhaps your dealer could acquire some more information oabout the fish’s origin (although this is difficult: the “last” origin” is not the real or first origin; but it is a hint that might be of some informative value.