As I know the Dewitt gold medal (given to his father in 1919) was in his mother ends at least at the end of Thirties. Dewitt was the lonely son of Dewitt family and when his father died the mother moved from Tenafly in 1936 to an unknown place. People from Tenalfy told me that they had relatives on the other side of the Hudson River and probly she moved there. So the destiny of this medal is unknown.