Thank you for reply Brink, what your saying makes sense however I have added two new images of the fittings:
This is the one that seems to fit fine:
This is the one you are talking about which seems to struggle to fit in:
I have tried screwing it the one you suggested too and there always seems to be abit of the screw that sticks out.
My bay drives have an automatic clip too so i dont think they require screws.