The bracket ZKC401 just seperates the two speakers and also braces against the heater at the top with the rubber buffer 616233.
The two console panels (left & right) are slightly different shape to allow the heater air to flow.
At the end of the two console panels nearest the gearstick there are two 'hooks' mount it to the H frame.
There are also two mounting points two on the engine side of the console panel screw to bracket riveted to the gearbox cover (part 44, 45, 46, 47 & 48) https://rimmerbros.com/Item--i-GRID600339
The original radio & speakers where dealer fitted