You are aware it's the same planform to the drawing you posted?
Plus NGB is 1/2 scale compared to the B-2.
EDIT: ...now I finally figured it out, I think you have the A-12 OXCART confused with A-12 AVENGER II. What you have is the NG A-12 AVENGER II submission, which shares its planform with the X-47 UAV and their NGB submission (which in many respects is a de-navalized NG ATB).
The rejected competitor to OXCART was Convair's KINGFISH.
<_< Serious, reread my post on the PlaneBucket submission thread, I said and I quote:
the other, other A-12, the rejected entry by Northrup for the ATA program and not the winning one that got can nor the CIA's version of the SR-71 Blackbird.
I know what I have.