How about a conspiracy theory: someone was in the process of making this into a 1943 copper but only got so far before giving up?
Usually, the simplest answer is often the best. Why try to remove a "4" and replace it with a "3" when it might be easier to alter an "8"? I vote for grease-filled die. Chris
Really? It is a neat coin; however, coins like this are virtually worthless and can be found all over local coin shows in 2X2's labeled "Mint Error" and selling for under $5 ONLY because the dealer does not realize it is overpriced?