Probably has a mix. My 840059(WY-50) has a mix of "vintage" and "new" blacks. Actually all 3 of my WYSE 'boards do.
The cool part about the 840059's is, as far as I know, they all have the thicker doubleshots. The spacebar is stabilized, though.
(And whoever got it for $20 shipped got a good deal: It's in much better shape than most I see at that price.)
Can you visually see the difference between vintage blacks and new?
Thicker double shots, yay everyone raves about thick double shots (that just sounds wrong), so time to see if I can join the bandwagon lol. The spacebar being stabilized is bad? Won't I need spacebar with my Moogle kit anyways?
Yes, the "bunch of cherries" on the logo is spaced out differently. On one, the "Y" in "CHERRY" is even with the rightmost of the cherries in the graphic. On the other, the "bunch of cherries" is raised up a bit. I forget which was which, but if you have both, you can check. The "vintage" ones should feel just a little bit lighter, and maybe smoother.
This is why I want to see a WYSE to USB adapter of some sort. They are solid keyboards, readily available in the USA, great keycaps, sweet layout, cheap, etc. Perfect travel/gaming 'board. I like the WY-30 best for that.
The thick WYSE ones are nice, though you may have to brighten them up a bit with retr0brite.
It's nothing special about the spacebar (though it's one of the longest at 9.75 units) being stabilized: It's just notable, as it's the only key that is stabilized. The later WYSE had thinner keycaps, that weren't stepped like that, and they had stabilizers. The WY-60 KB has the same layout, even.