Like Ken stated there are bunch of 57D's. Jean list 144 in her book. In the BIE Handbook there are 568 listed but they are a lot easier to ID. Using the Hardy Index System your BIE is a 57D-4DH. "4" a break between the B & I. "D" indicates a break of ½ or more, but less than ¾ of the height of the letters. "H" indicates a partial die break extending from the highest level of the letters toward, but not reaching, the lowest level of the letters. This type is termed an "upper" break. From the 568 listed we are now down to 3 as there are only 3 57D-4DH's listed and 2 of these have a Die Chip in the lower loop of the "B". That leaves the 57D-4DH+3 as the only possible listing. Your coin is a very close match to this but missing a small hook at the bottom of the break which may be covered up by the gunk on the coin. I can't find any match in Cohen's book for your coin. Remember the illustrations in both these book are hand drawn.
Bottom line is that this would be a new listing on COC. Can you email me the images of this coin and I'll list it.
JC