now I find a few minutes to write a few lines to this topic.
I remember reading in the 90's, that the US Navy was very sceptical of canards during carrier approach and landing. That was one reason that Boeing, L-M, MDD and N-G cut off the canards on their JSF carrier variert design concepts .
So I wonder if this model still represents the NAFT design concept DP527 as shown and written in the book "Air Force Legends: Northrop YF-23 ATF by Paul Metz"
. Maybe N-G tried to please the US Navy and did some wind-tunnel tests with this model without the canards.
Another design concept designation like DP527 "letter" or DP5##.
On page 74 of that book you see a same model of the design concept DP527, but the label on model base writes DP531.
The design concept DP533, also shown on that page, has a conventional tail and no canards.
Maybe Tony Chong might give us some more information.
Anyway, great find and pictures, Airplane and Mark!!!