The billionaire who buys this will almost certainly not allow that kind of access. If its in a public archive its much easier to get that kind of access.
Someone in another comment said they got to see it in an exhibition 20 years ago. So it sounds like even if it’s in some billionaire’s collection it’s taken care of and the public does get an opportunity to see it, at least sometimes.
Someone in another comment said they got to see it in an exhibition 20 years ago. So it sounds like even if it’s in some billionaire’s collection it’s taken care of and the public does get an opportunity to see it, at least sometimes.