Under Feist Publications, Inc., v. Rural Telephone Service Co. ... it gets tricky.
From Wikipedia:
> The ruling of the court was written by Justice Sandra Day O'Connor. It examined the purpose of copyright and explained the standard of copyrightability as based on originality.
> The case centered on two well-established principles in United States copyright law: that facts are not copyrightable, and that compilations of facts can be.
> "There is an undeniable tension between these two propositions", O'Connor wrote in her opinion. "Many compilations consist of nothing but raw data—i.e. wholly factual information not accompanied by any original expression. On what basis may one claim a copyright upon such work? Common sense tells us that 100 uncopyrightable facts do not magically change their status when gathered together in one place. … The key to resolving the tension lies in understanding why facts are not copyrightable: The ″Sine qua non of copyright is originality."
> ...
> The standard for creativity is extremely low. It need not be novel; it need only possess a "spark" or "minimal degree" of creativity to be protected by copyright.
> In regard to collections of facts, O'Connor wrote that copyright can apply only to the creative aspects of collection: the creative choice of what data to include or exclude, the order and style in which the information is presented, etc.—not to the information itself. If Feist were to take the directory and rearrange it, it would destroy the copyright owned in the data. "Notwithstanding a valid copyright, a subsequent compiler remains free to use the facts contained in another's publication to aid in preparing a competing work, so long as the competing work does not feature the same selection and arrangement", she wrote.
> The court held that Rural's directory was nothing more than an alphabetic list of all subscribers to its service, which it was required to compile under law, and that no creative expression was involved. That Rural spent considerable time and money collecting the data was irrelevant to copyright law, and Rural's copyright claim was dismissed.
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And so, my (I am not a lawyer) take on this is that the numbers of the model are not copyrightable. The selection of the source material is... kind of. This gets into a "a recipe is not copyrightable, yet a recipe book is"
The model may, however, be a trade secret. ( https://en.wikipedia.org/wiki/Trade_secret )