Unmarked Jadeite - Vintage or Repro?

I love Jadeite. So my heart skipped a beat when I saw a stack of six dinner plates sitting on the shelf at my local thrift store. When I flipped one over, I expected to see the familiar Fire-King logo but was surprised to discover that they were completely unmarked. They were also in phenomenal condition without so much as a utensil mark. Immediately, red flags went up that I was looking at reproductions, not vintage glass. If they had been marked, I would have snapped them up but now I stood in the aisle, pondering whether or not they were even worth the price the store was asking.  I finally decided, "What the heck. Worse comes to worse, I'm stuck with some pretty cool looking glass plates and I haven't broken the bank" and loaded them into my cart.

Now the fun began. First, I Googled 'unmarked jadeite dinnerware'. I found out very quickly that Fire King made lots and lots of unmarked dinnerware. That was encouraging so I pulled out my Fire King reference book, Anchor Hocking's Fire-King & More by Gene and Cathy Florence to see if my plates matched a Fire King pattern. There it was - Restaurant Ware. Then I measured a plate to make sure that the size corresponded to one of the plates in the book. It did. I called Becca over to take a look. "Check it out. Ten inch Serving Plate. It's the only jadeite plate in the book that size". Then I pointed at the book value - $150.  That's per plate. Now, I know book value is generally inflated but all of a sudden, finding out whether or not my plates were vintage took on a bit more importance.

Becca happily manned the desktop while I used my Google Fu on the laptop.  For the next hour or so, we shared our new-found knowledge and came to the conclusion that if our plates were repros, there were only two possibilities - they were cheap Chinese knock-offs or FireKing2000, a Brazilian product meant to revive the Fire King line. According to the collectors' website FireKing.net, the FireKing2000 restaurant ware never made it into stores and the Chinese repros measure 10 1/2".

Can I conclude that my plates are the real deal then?  Not yet.  I would never stake my reputation on one night's worth of Googling and my limited experience with Jadeite restaurant ware.  It's time to find as many experts as possible, examine their collections and let them have a look at my plates.  Only when I am certain beyond a reasonable doubt can I offer these for sale.  In the meantime, I plan to have fun researching!