Christmas tree pins are one of the most popular niches in the costume-jewelry figurals category. Holiday brooches are widely collected and sought, the most desirable being valued over $200. While most attention has been given to signed jewelry, unmarked pieces maintain an aura of mystery that maddens aficionados determined to solve a pin's provenance. Who made certain beautiful or unusual pieces? Was it Eisenberg, Carnegie, Weiss, Robert, Sandor,...