Hall China made several shapes of coffeepots to be fitted with metal drippers. These usually have a Drip-O-Lator backstamp with the name of the maker of the metal drippers, The Enterprise Aluminum Co. For some reason, the Hall name isn't included in the markings for these coffeepots.

Hall Drip-O-Lator Shapes minus their drippers
“Waverly”	“Panel”