It must be frustrating, and I can sympathise as there is a considerable amount of work in developing an accurate 3D model that prints well.
Unless they are somehow leveraging your research or 3D data, I don’t understand why anyone would produce a copy of a model that is already available - it needs the same work as any other model, and the market is inevitably limited by the presence of a competitor. But it’s a free world.
Perhaps you could react by advertising more and undercutting their prices? “Buy the original, not a copy”. It’s a sort of “porcupine approach” to marketing that suggests that you will try very hard to hurt their efforts if they tread on your toes?
Of course if you do “up the ante” they may also react. As I say, it’s a free world.
