I looked at the picture a couple of times and appears that the item is more than likely iron than lead or white metal....but then again my eyes aren't as sharp as they used to be....lol.
I dug what I was almost certain was a heel plate last summer.....I was only partly right as it turned out it was a heel plate all right but from an old golf club....lol.....that would also explain the big number 3.
As to age I would guess 50s to 60s. It is from a store line of clubs not a pro shop line of clubs. It looks kind of like those that were sold by Montgomery Ward back in the day.