But it's never too late. With internet now it's so easy to always find even sought after pieces whether through dealers, collectors, fora, or auctions. Years ago it was almost impossible to find a specific piece if you didn't catch the train when it was launched but now it's easy to find a Lorenzo de Medici or Hemingway in a couple of minutes.
As for the Proust I have to agree with your remark regarding posting the cap but I don't screw it on fully, just enough so that it doesn't fall...