Which Rodin sculpture was cast while he was alive?
There is only one work in the show that we know was cast when Rodin was alive: the portrait bust of Gustav Mahler. The portrait of Father Pierre-Julien Eymard was possibly cast in his lifetime, or within a few years of Rodin passing.
I find it interesting that even if there were multiples cast of each work, every piece has a slightly different surface patina that makes it unique.