The DP-2 project of duPont Aerospace
Yep, that's the one WK!
The brainchild of Anthony A Dupont it was to be a 30-44 passenger transport with side by side engines that incorporated thrust vectoring.
I found the DP-1 (a scaled down two-seat proof-of-concept) first and surfing over the net I found out what it was.
Also found that by googling. Interesting.
All yours WK.