I got this at my local coin shop a couple days ago. It is a 1940D Mercury Dime class 2 DDO. Wexler has it listed as WDDO-002 (strongest of the 9 known DDOs for the date). You can see the notches on the flag of the "1" on both sides. There is a separation line down the entire right side of the "1" as well. You can also see separation lines on the "9" in the loop and tail. You always need to be on the hunt because you never know what you may find!
I think this is because the doubling is fairly minor on most of them. Not intending to discount the coins in any way as their are folks that really love these, but in most cases, you really have to look hard to see the doubling as it's a very specialized degree of variety collecting. Is there ANY doubling anywhere else on the obverse of the coin? For example, the 1941 DDO shows similar doubling to what you've shown but the motto shows a much better example.
This die is listable on CONECA's master listing but it is not on there yet because no one has submitted an example to Dr Wiles for attribution before. Also, there is doubling of the motto and designer initials in addition to the date. I just didn't post any pictures of that.
If you would like to learn more about Mercury Dime varieties check out these websites (they are a lot of fun to hunt for and collect!): http://www.arsave.com/variety_resource_dimes http://varietyvista.com/Mercury Dime Files/index.htm http://doubleddie.com/754334.html http://doubleddie.com/499534.html
