Man, looking through a few hundred 1957-d's and its hard to find one without a die chip. Its getting to late but im wondering if one of those is a doubled die? The 9 looks the part...and the lettering is fat and rough..
Nice. They can be found in all years but the 1950's seems to be when you find the most. Here are 3 from 1994 (yes even on Copper plated zinc cents) I found in a roll -