Fighter Master FIN: here is Yak-45 STOVL derivate with canards instead of horizontal tails and on the right is simplyfied drawing of original
Yak-45.
Stealth Spy 1: "obscure thing" is Perspektivnij Frontovoj Istrebitel - perspective fighter competition, which finaly led to Su-27 and MiG-29. This
Yak is from 1972 proposals.
Stealth Spy 2: I have only one another picture of MiG Izdelije 33, but still that model in grayscale.
SOC: Drawing was made from the same wind tunnel model, as the hand drawn plan, that you mentioned. I am not 100 % sure, if it was definitely applied
to final version of MiG Izdelije 1.27, but it is possible.
Intelgurl: As SOC wrote, for fighter it is much more usefull to have roud shaped nozzle with 3D vectoring. If you have flattened nozzle, you can
vectore it only in 2D up and down {YF-22} or left to right {Bird of Prey and also X-45}. F-117 had low IR nozzle, but the price is enormous heat
loading, when the hot gasses pass trough rounded cross-section to near pencil shaped nozzle. There were some attempts to build low IR 3D nozzle in
Soyuz R-179-300 engine, but it was very complicated. Instead of this, perspective russian fighters will have AL-41F or simmilar engines.