There is a book about anvils . Do you have it?
The base of the anvil is cast. And obviously so, by looking at it.
The body of the anvil is forged from wrought iron. The body of an anvil is not the base. They are two entirely separate components. If you have the book, and read it, you would know...
The base of a Arm &Hammer anvil is not in anyway forged. These are cast of an inexpensive steel. That is why they exhibit the familiar casting lines of the sand mold.