My super heavy artillery tank only has 2 shells that I can use for the model. I want to make a bunch of copies of the plastic thing. I am not sure as to how I should go about that. How can you make larger size molds? It is a couple inches big and I dont want to use GS as it is a bit expensive. I don\'t like using sculpey stuff as it doesn\'t hold the details well, perhaps I am doing something wrong with this. All ideas welcome.