The recent cards from Turning Stone in Verona, NY have the TS logo in a white square at the top right on the front. The first reported cards were the brown Topaz card had an "A" on the top right of the reverse, the red Ruby card had a "B", black Onyx and blue Sapphire with no letters and the grey Prestige with an "E".

Just reported were brown Topaz and red Ruby cards with NO LETTERS.

And what appears to be the very latest card is a brown Topaz card with no letter on the back and the card is now a flat non-metallic plastic where the earlier Topaz cards were a metallic finish. The other difference on the new card is that the vertical pattern down the right side of the card is now very distinct where is was very faint on the earlier cards.

Here's scans of one of the earlier Topaz cards (without the letter) and the latest Topaz card. Reverse are identical.