Martin at Penfolds used to fit them, not sure how in practise he is and I have seem one adjusted by another well known South East fitter who had made a right hash of it. Mostly you are tied in to the UK agent, I used to fit them but even when authorised to fit them by the US owner I was blocked from getting hold of even numnahs for them and life was made rather difficult for me in connection with RPs. I stopped doing them as I feel you need to be fitting them regularly to keep your "eye in" as it were.