The Boeing Phantom works, the secret design facility of Boeing,  had to wait for many years until this Technology Demonstrator was allowed to be revealed by the USAF. The plane, called the "Bird of Prey", was a demonstrator in order to validate design techniques later used in the JSF program. Also, it was used for getting experience on designing low observable radar components.

The plane completed 32 test flights between 1996 and 1999. In order to save money, components were used were possible of existing planes such as from a Cessna Citation. 

Obviously, no model existed of this Bird. But I wanted to have one in the collection and it can be done.

From Flight International magazine, issue 29 Oct- 4 November 2002, data was obtained and the drawing published was scaled up to a 1/72 scale plan. The wingspan is said to be 23 feet. Also, various other sources on the Internet showed pictures to get a feel for this model project. 

In order to get some basic parts, I bought a cheap Italeri X-35 kit and "kitbashed" it using also various parts from the scrapbox and plastic sheet. 
kit box
With sanding, cutting and using lots of filler, the basic fuselage shape was made first. After that was about OK, the wings were made using spare wings from a F100 I had. The wings and tip fins are set at an angle and the various smaller parts of undercarriage and doors were from the Italeri X-35 kit. I also used the kits canopy, seat and cockpit instruments as a basis. 

After sanding, filling, sanding and filling..... the shape was about right. 

The cockpit area was painted, using also the kit's seat and the canopy added and the gaps filled. After that, also the basic undercarriage parts (made from the kit parts) were attached.
 

to  page 2 of Bird of Prey