ringo wrote:what's the golden socket under and to the right of the drive shaft?
KERS related, or is it some kind of auxiliary mounting?
That's the gearbox cross shaft, every F1 gearbox has this part. It takes the motion from the gearbox and translates it 90 degrees to drive the differential.
The great part about this cover\shaft is that its height is pretty much fixed by the regulations, making it a useful reference point for assessing diff height of suspension geometry. As the gearbox input shaft height is fixed by the crankshaft height rule (58mm) and thus the gearbox shaft spacing rule (85mm) then fixes the output shaft which this is inline with at no less than 143mm.