Adriatic,
Thanks for the thoughtful response.
People do build models and people do buy models. A model is only a representation. It could be made of paper, clay, plastic or any material. Architects build models, or used to, that didn't include structural inside components or anything. A model could be devoid of detail whatsoever. If one wants to call an MTH Railking K4 a model that is fine, the only thing left is to measure and discuss the accuracy and attributes of the model compared to the prototype. It'll be a matter of fact discussion. The people who are building the models Art is discussing are professional model builders. That you did not build the model does not disqualify something from being a model. I may be misunderstanding something you are saying also, but the fact that money has been exchanged to buy a model does not disqualify it from being a model.
