I just bought this Trenton anvil for $475.00 and I am wondering what year it might of been made? It has an hourglass bottom and the Trenton stamp and USA on the side.The front or horn side foot on the left has W158 and I know that is the weight wich is close to the actual weight of 156 pounds. And I know that the left is the serial number and it is A23281 but the one at the end almost looks like a Z and I don't know if that was a thing they did or not. Thanks if you can help tell me what year it might of been made.