In reply to droites:
From memory, I think the black trigger was for everything that wasn't a Taakoon. It might be worth considering the option of installing it 'backwards' and then sawing off the metal trigger bit, as the rear does stick out quite a lot when they're on the right way round (on the Taakoons, at least.
Maybe also look into using the Petzl Trigrests instead, since they seem a bit more generous and ergonomic - you might need to take out the middle finger-rest bit and put a spacer in, and maybe some old inner-tube or griptape round the shaft underneath to help keep it in place.