While I'm almost certain it's a reproduction (and a pretty nice one at that), wouldn't that be amazing if a dealer put a genuine super rare coin in his junk box? I'm sure it's happened before.
True however I've been at shows where someone has cherrypick a 1888 hot lips Morgan and a 1942/1 dime out of the junk box/ half price bin.
You hear those sorts of stories from time to time. There are many, many, many, many different varieties out there, and many dealers aren't fluent in all of them. A dealer also doesn't have time to sort through his junk to find them. A regular, circulated 1942 dime is worth a couple of bucks, and the dealer gets a lot of them. Its just not worth it.