@PaNT3rA . Check your suspected DDs against the following references Doubleddie.com Varietyvista.com I think there is another under copper coins or Lincoln cent resources They list the confirmed DDs. See if your find matches any. You'll also get the added learning of looking at lots of true DDs. The more you look at, the easier it will be to spot one (and not waste time with the No Value Doubling (NVD) [Somebody started using NVD on here the other day and I liked it]
