The Bartini A-57 with the Tsybin RSR strategic reconnaissance parasite plane - the A-57 a V/STOL Mach 2+ seaplane bomber to be refueled by submarines and the Tsybin flying Mach 3; cancelled in 1958
The FMA IA 36 Cóndor, a concept designed by Kurt Tank for Argentina, with five RR "Nene II" turbojets in an annular configuration around the rear fuselage - cancelled in 1958, cutaway by @Motocar_cutaway