Testor's predecessor, Hawk, had a history of making "secret" kits. They came out with a kit of the U-2 as well as the AB-1 nuclear powered bomber.
It was amusing to see that that the company's "Mig-37 Ferret" looked more like the F-117 than the F-19 kit did. But by then we knew what the F-117 looked like.
I did not build my F-19 kit as a stealth fighter but covered over the intakes and added winglets and a rocket nozzle to make it a spacecraft.
The F-117 was never a fighter, but got that designation because the general officer in charge of TAC said that it would be flown by the USAF's best fighter pilots and that no such pilot would ever want to fly any "attack" aircraft. The "117" designation came not from extending the old Century Series numbering last used with the F-111 (the USAF F-4 originally was know as the F-110 and some people claimed that the F-15 and F-16 were also known as the F-112 and F-113 but that is pure BS) but because the highly classified program was known as Program 117, and when it came time to print the manuals they stuck F in front of that.
By the way, the F-117 in reality never went out of service and has been used against ISIS for years. They dismantled them and stuck them in a hangar at Tonapah, NV, their original base. This not only made it easy to load them in a C-5 and ship them out but also makes it impossible to tell if some of them ended up in the hands of a friendly Air Force (IDF?).