Ancient Celtic Hallstatt Culture Bronze Shield Boss Umbo

A large ancient Celtic, Hallstatt Culture circa 1200 - 475 B.C bronze circular shield, boss also known as an Umbo adorned with a characteristic for Celtic armour, punched design and pierced on the center with rivet hole for attachment to the shield.
 
 
 

 DIAMETER: 13.5 cm (5.32 inches).
 

 CONDITION: Showing its age and usage with a heavy green-brown patina with earthen and mineral deposits, a minor flaw in the structure of the metal on the edge (please see the picture).