I think I've located this component now. Rather than facing you once the glovebox is removed, as all the pictures show, it is tucked away up on the top of the ventilation ducting. It's just in sight and just reachable if you poke your hand up there. I think it will be a devil to remove and replace, needing a mirror to locate the fixing screw(s), but I will have a go shortly. Thanks again for your help, Big Kev.