My first thought is it looks like a cross between the X-47B [0] and the RQ-4 Global Hawk [1]. Interestingly, both of those came out of Northrop Grumman years later.
[0] https://en.wikipedia.org/wiki/Northrop_Grumman_X-47B
[1] https://en.wikipedia.org/wiki/Northrop_Grumman_RQ-4_Global_H...
Northrop's Tacit Blue might have been the influencer for both programs: https://en.wikipedia.org/wiki/Northrop_Tacit_Blue
There were no facets on this plane because that really only came about after Ufimtsev's paper described how to calculate RCS. Computers at the time of the Hopeless Diamond/Have Blue/F-117 couldn't run those calculations on curved surfaces. Which meant Ben Rich's team used the flat surfaces (I don't recall exactly who suggested it, but it's in the book).
I'd also be curious if Boeing had any thoughts in the areas of radar absorbtion/dispersing paint in the 60s. I recall the SR-71 Blackbird had some of those properties in it's paint (though the paint was mainly used for cooling).
So it looks like they stole your idea.
