Hi Veni -
It's an interesting looking coin, but I'm fairly sure you won't find this in any coin error book or website, unfortunately it's what's known as a grease filled die or weak strike, it only appears like there is a "1" over the "4" because the < part or the 4 was filled with to much grease at the mint, Still a very cool looking coin.
This minting error is worth a few US dollars. The coin in the picture might sell to an enthusiastic collector for $3 to $8 US dollars. A dealer would pay, perhaps, 50 cents or one dollar for the coin.
Happy Hunting.