OOH er missus!
Pulling off the cap reveals a bit more of the button - however it rattles within the main "structural" part of the handbrake handle! which unfortunately doesn't seem to be accessible!
I got the brushed chrome grip as part of my freebies - can't believe they want £45 for that! in the end i fitted the metal bit in with my original silver caps - looks pretty good to me as the handle is now totally silver looking and saved me having to meddle with the leather boot.
Also ordered up the silver footrest plate - looks pretty good and a doddle to fit - and the clear look front indicator bulbs or so i thought! turns out it's £10.50 per bulb so i'll have to cough up some dough for the other one! oops!