This is Short Brothers, a manufacturer of airplanes and missiles in its final days. Perhaps the most significant of the brand was the Short Seacat due to its proliferation.

-As no other manufacturer of this missile's engine from the late 1950s and early 1960s is known, the engine was possibly produced by Short itself as well. Investigation continues.

-It has four output nozzles, and was divided into two parts, the first part for take-off aid or boosters and the second part consumed as a sustainer.

“Short's Seacat”