Hello all, I have ended up with a Garmin handlebar mount for a 500/510 (might be a bit short for an 800 but could try it). It’s black and would hold the Garmin ahead of the stem for a more natural view. Only slight issue is the bolt is missing but, it should be easy enough to source one.
More info here http://www.racewaredirect.co.uk/#/garmin-mounts/4572268838
They are £30 + £3.50 new. This clamp is new just no bolt. Yours for £15, I won’t charge for P&P 😉
Jonathon