Azael

I was wondering how, in medieval times, "flanged maces", like the Thames River mace (see below), were forged. All examples, of Smiths making one that i could find, involved using modern Stick welders to attach the flanges to a core tube. But how would you do it without? Would you forge a solid, sizable cilinder/ball at the end, chisel in the general shape of the flanges and then finish using files? Or are the flanges somehow slotted into the socket and then forge weld? Just curious.