Nicest pin ever? Or was I screwed?

Harry Truman ran shoestring presidential campaigns and as a result his pins are pretty scarce and can be costly. I've passed up quite a few on eBay and elsewhere because I thought the pin was too expensive or the dealer wasn't sharp enough to know if he actually had an original.

A week before Christmas I found one on eBay that looked pretty nice, was not too expensive (about $24 IIRC), claimed to be original and came from a dealer with near perfect feedback (lots of it).
The pin arrived the other day, I pulled it out and it looked like this:

The scan doesn't do it justice. It's shiny and just perfect. Flawless celluloid surface. I thought it was the nicest 40's era pin I'd ever owned. And then I turned it over. Again, flawless. And that's the problem.

I've been collecting these pins for a long time. I can't remember ever seeing a supposedly 60+ year old pin with a perfect back side and pin. Never. These babies were made with the cheapest possible alloy and they stain and tarnish over the years no matter now well they are kept.

So now I have a question in to the seller. He seems like a very nice guy, emailing me about sending the pin out after Christmas if it wasn't something I needed for a gift. And his feedback is almost perfect. I asked him if he was certain that the pin was an original and not a reproduction. And I was very polite about it. So I'll be interested in hearing what he has to say.

UPDATE:
I was contacted by the seller today (Monday) and he provided me with enough info and a backstory on his pins that I'm pretty sure the pin is original. Looks like I made a pretty good deal.