As I said upthread I brought up this issue to a career entertainment lawyer who does who works to clear I.P. for movies and videogames: likenesses and images and characters, the works.
He explained the difference between using images that are clearly in the public domain and those which are considered transformative work
or work added
, and based on my brief explanation said that it sounded like the latter. He also was pretty clear that absent other evidence these images would not be public domain (unless the Copyright owner expressly released them) in the first place. He obviously would not offer an actual legal opinion or advice without knowing all the facts, but he was pretty clear about how the law generally treats such items.
So, respectfully, I've consulted an expert on this, whereas lay opinions given here are just that.