Quote - > Quote - when would a model become my own?

I have a model of a train paid for.

I have taken said model and chopped it up.into about 8 sections. removed parts of the body. copied other parts and added them. changed the scale of others.

so how much do I have to change to make it my own to do with as I wish,

with out sued?

or would I have to start all over. even if I liked the shape so much that if I did start over it looked like the first one after I had finished chopping?

...

At first glance, I don't understand why anyone would want to sell or distribute something, even in part, which was created by someone else.

Trying to look at it from a non-modeler's perspective it could be like this: I want to have a good train-model, but there is none. There is a train-lookalike, but unfortunately, the different parts are completely out of scale, taken from different actual trains and so on. There is this train-expert who is not a skilled modeler, but knows trains, rearranges and rescales the different parts of the first model into a new one, and the result is the perfect train. This is what i (the consumer) want. Of course the train-expert should get at least some money and fame of it, otherwise he would not have done this work in the first place, even if all parts he used were essentially copied. As long as the end-result is to be considered a different thing than the copied parts, it is a creation of its own.

The decision however, if the end-result is a new original work or merely a modified copy, can only be made on a case-by-case basis. In the meshwerks/toyota case there was no originality involved, even though the objects were completely different things (computer-model vs. car), on the other hand for example Jim Gary shamelessly used rearranged car parts to make himself a name (would he have tried to do this with some 3d-vendors car-models, he probably would have experienced some more resistance :-).