This part is a bronze steering wheel for Elco 80' PT boats. It has a 1/16" shaft. It is designed to be more rugged than plastic, particularly for R/C boat use. For further details of the helm, please see this page:
http://www.pt103.com/PT_Boat_Components_Helm.html">http://www.pt103.com/PT_Boat_Components_Helm.html.