IANAL, but Crispin Glover sued the creators of Back to the Future II for using a mold his face as George McFly without permission [1]. While he starred in the first film, the second film used a mold of his face since he ended up not joining the project.
I’m not a lawyer, and don’t know what jurisdiction you are talking about, which celebrity you’re talking about (alive/dead/long dead, where do/did they live), etc, but I think the model copyright will be yours, but you will be restricted as to where you can use it because others have the right to make money with its looks.
Law works similar with copies of physical objects. For example, you are free to make a 100% copy of an iPhone, the Mona Lisa or a pop song and enjoy them at home, but you can’t display them in public or sell copies, or even give them away (did I say I’m not a lawyer?)
[1] https://www.hollywoodreporter.com/thr-esq/back-future-ii-a-l...