I've done a little searching but i've found nothing on a error like this yet. Opinions, thoughts, comments welcome...
this is called damage , the whole coin is badly damaged. this is probably why someone put it in the roll , so they could get rid of it .
The first thought that came to mind was a grease filled die that broke loose...(strike through?). Is the mark incused?
the mark is raised almost the same height as the 9 itself. and coneca has a listing it fits, i just can't find an example i can compare it to
http://www.varietyvista.com/Variety%20Master%20Listings/lincoln%20doubled%20dies%201909-1929.htm and it seems to fit the very 1st entry as an engraving error/issue but i can't not find an example of it to compare to.
On just about any old pitted and corroded coin there will be all kinds of odd looking things due to the pitting from corrosion and all types of other damage over the coins lifetime. When I first saw this coin I thought of the old ebay lady that was selling what she called 1909 S VDB cents. on some of them she said she could see numerous S mintmarks. All of her coins were pitted and corroded about as bad as this one.
If this was anything, it would be repunching. That is not doubling as the coneca listing describes. Read this for mor einfo. http://www.pcicoin.com/DieDoubling.pdf I have to agree with damage in the form of a "nicely placed ding"
