quick follow-up - here it is painted and a single wrap of eletrical tape (to give the Givi mount clamp something to 'bite' into):
inside Givi Airflow screen:
Power is coming from the same location - on a test ride, I found that bumps in the road actually made it bounce a little too much - so I bent the aluminium arms some more and then basically wedged some rubber discs under the Givi mount bracket to provide pressure from the top of the clocks - the 'spring' in the aluminium is now kept in check and you cannot see the rubber - its now very secure, the only play or 'spring' in the Givi quick release mount itself, which was there beforehand on the bars and doesn't interfere on anythig but the bumpiest roads.
Quite pleased - it's a much better location than the bars - also its better protected as it nestles inside the screen so out of rain while moving.
I was worried that there may be an effect on the aero properties of the screen - 1 because the aluminium brackets change the angle anf position of the screen (it's 2mm further out at the bottom and slightly more out at the top of the bracket which changes the angle ever so slightly) and also 2 because the Sat Nav might have had an effect on airflow under the screen by being in the way - but having tested it on the motorway yesterday, I needn't have worried, it made no difference at all!