Part of the problem is that they put the 118x PCB design in new 128x boxes and while the main sticker on the card that you can see through the box has the 128x part number there is a second smaller sticker that you can't see with the 118x supplementary part number. Only way to be sure is if you can see two stickers with the 128x number on them in that opening on the box.
the 128x-RX are just recertified cards, so they might actually be the older PCB design
I'm glad I didn't get the block for my card yet; no telling which PCB I'll get back from them :(