Images courtesy of the Katie Klein Collection.
After watching several online clips from Snow White's Golden Anniversary Parade, it's quite difficult to see if the dwarfs are actually wearing the belt buckles.
They were later available for purchase at the Disneyana store on Main Street U.S.A. A numbered Certificate of Authenticity was included. Reports online indicate that the buckles were limited to 500.
Additional images via robotsandthings.
A 50th anniversary heart-shaped metal necklace was also available. Approximately 2.375" X 2.375".
Necklace image via gneice.