My first thought is that it is machine doubling, however I'd like to see a better close-up. I'd like to examine the top, left of the mintmark. Chris
If were machine doubling I'd expect some doubling on the date as well. Could you post some closer images of the 9 and 5?
Looks like a D over D to my eyes. I don't see any other doubling that might indicate machine doubling.
There isnt any other doubling on rest of coin only on the D. I looked on variety vista and couldnt find this rpm though
That's very interesting. According to the Lincoln Cent Resource, there is a 57 D/D/D. When you look at the image on Lincoln Resource, I'm not sure if your coin matches it. It's got some similarities, but wondering if your coin is worn, some of the diagnostics are worn off. Image courtesy of Lincoln Cent Resource
That's a nice find. Get out a toothpick and try to loosen off whatever you can of that green crud before it grabs on and won't let go. It's verdigris, it forms on copper, and it was used to add color to paints. Soak the tip of the toothpick in water or acetone for about 10-20 seconds so it's not as abrasive. Save this nice example. It's one of the more unusual RPMs.
Great Find. I am envious, but glad to know the variety is out there. I might need to go through the 30 rolls of UNC 1957 D cents I bought for face 45 years ago.
Click on the OP's picture for a larger view. It looks like a D/D to me but the mintmark is further to the right than the one in BostonCoins' picture (line up the left side of the MM with the loop of the 9 above it.)