Sales to customers located in the same State as the establishment
are sales made ``within the State'' even though such sales may
constitute activity within the interstate commerce coverage of the Act,
as where the sale (a) is made pursuant to prior orders from customers
for goods to be obtained from outside the State; (b) contemplates the
purchase of goods from outside the State to fill a customer's orders; or
(c) is made to a customer for his use in interstate or foreign commerce
or in the production of goods for such commerce.
