I agree with Reality Forgotten on this one.
However I am not qualified to give legal advice, so this is nothing more than a friendly suggestion.
You should seek the advice of an Attorney if any copyright is questionable.
Quote: "and he says that the people who own his paintings/drawings have gotten a copyright"
That sounds preposterous to me.
So if I buy a book about Little Red Riding Hood that was abandoned by the publishers years ago, then I now have the right to claim it as my own?
I think not.
Once something is deemed "public domain" then no one can lay claims to it.
If so, you would have 200 million people trying to claim it at the same time.
Unless the creator of the work (Leonardo in this case) sold or transferred his copyrights (which didn't exist back then) how can the new owner claim to have any rights other than ownership?
The whole issue of copyrights is bunch of bs to create legal expenses and fees.
Who can prove that he was the Author of said works.
He may have been drunk out of his mind and his apprentice did everything while he was passed out.
How do you know?
Anything that old is public domain in my opinion, and as Reality Forgotten has pointed out... his works have enough historical and sociological significance to warrant the status of public domain.
The whole question of ownership of art that old can easily be questioned.
History will show that it has repeatedly changed hands by the acts of war and theft.
How can they claim ownership if they bought it from a thief?
How can you prove its legitimacy when it spans that many years throughout history?
This is the subject of a debate that has lasted many years, with many countries making many rulings.
How then can something that has relocated itself (through its owners) through so many jurisdictions ever hope to claim that is has been bought and sold according to the law throughout its history?
Only the Museums try to claim Copyrights on things that belong to the World.
They need to overcharge for their prints, so their administrators can afford their new Lexus.