The mint mark is proving second punch and actually, it is a small date over a large date, and the shape of "0" and the bottom part of "0" is proving that too.
Not seeing a large date over small date. The date in Your coin needs To EXACTLY match the pictures that other members posted. Close isn't good enough and and having a RPM without the date matching, doesn't work either
It is a small date over large date not a LARGE DATE OVER a SMALL DATE, many times I corrected but still repeating! and why it needs to exactly match their coins? This is a different coin with unique and new characteristics and values! Aren't you agree?
No I don"t agree. The 1960 cent whether it be a D mint or a philly has been one of the most collected and scrutinized coins in the series. You might be able to find your variety on http://varietyvista.com/index.htm or http://doubleddie.com/ or https://coppercoins.com/ It may be a variety, that we are unable to see due to poor photos. But , there is nothing there to conclude a Large over small date.
Some things: There was only one D punch used, so no possibility for different sizes. The pictures that clearly show the Large Date/Small Date show the quality of picture you'd need to show to have anyone confirm that is what you have. The 1960 Large Date/Small Date is a doubled die, specifically a "design hub" or "Class III" doubled die.
Lemme introduce you to "Doubled Dies" See, the term "Doubled Die" comes from the doubling being ON the die. Every single coin struck with that die will look exactly the same. Because the doubling is ON THE DIE. Hence the term "Doubled Die" SO, for this to actually be the overdate for the 1960 D, it is a REQUIREMENT that all diagnostics match. If it doesn't all match, it's not THAT doubled die. As far as the mintmark, that's a different issue and as in 1960, the mintmarks were hand punched onto the dies, it's NOT part of the doubled die. If anything it would be a repunched mintmark, where the guy wasn't happy with how it looked so he punched it into the die face a 2nd or 3rd time, but slightly off. A RPM has nothing to do with a Doubled Die whatsoever. It's two completely different events. Now, I am not here to argue the definitions of long established hobby terms. Feel free to submit your coin for authentication and attribution to a third party grader of what you think it is, and they will tell you what it is or isn't for the fee. You ask for an opinion, you get them then you attempt to "plea your case" as if anyone here with knowledge and experience is going to change their position on it. That's unlikely to happen. My opinion, this is a well circulated, average, 1960 D cent.
Your coin is a 1960-D small date. The rare over date is the one shown in post #10. The bottom photo makes it clear. Your coin does not match any of the markers.