The States and ATB Quarters are easier to search for doubled dies. Just look at the centers of the designs. That is where 98% of the DD's are on the two series. (Because all these are the single squeeze dies.) Just two dies are known to not be found on these areas.
Levelsofmadnes, I would hold onto it for now. If you went to send it in, send it to Tanner Scott (Tanman2001 on CCF). He's the owner and administrater of crdievarieties.com. He'll do attributions for free. You'll only have to pay return postage. He does it fast and will only take one to two weeks.