Liking the direction of this- Can't go wrong with Genies- very cold war.
Same with Firestreaks. It was only missile which was designed in reverse with the engine in the front, the guidance electronics in the rear and the power system at the back... 
Not quite. Firestreak's layout, front to back was:
Seeker
Front proximity fuse ring (sensor windows)
Guidance electronics
Control electronics
Fuse electronics
Rear proximity fuse ring (sensor windows)
Control Actuators
Motor and wings
Warhead (wrapped around blast tube)
Control fins
Air bottle (wrapped around blast tube)
Compressed air from the bottle at the back went forwards through pipes to the control actuators, which then moved long rods which went back down the body to the control fins. The reason for this was probably weight balance and the bulk of the systems. Firestreak's valve electronics needed cooling, so putting them around the blast tube probably wasn't an option, and it was probably thought better to have reliable rods running past the motor than fragile wiring, so the actuators were put in the forebody too. When you've got all that stuff in the front, the only place left to put the warhead then is in the back.
Red Top, with the advantage of experience and solid-state electronics that were both smaller, and actually needed
heating rather than cooling, could put it's control electronics and actuators in the rear, which gave the more logical layout.

