Best I could do without pulling the seat out.
Little sketch of the mount I made is attached too.
It's effectively 2 lengths of 5mm thick (approx 100mm wide) steel plate with a slight bend in it to match rear mounting points and at the front it has 2 tabs welded to align with the front mount points. I then put a support beam across to keep both sides aligned.
The side mount rails then bolt on top of this. It's a little bit of a jigsaw to put in (first base plate, then side mounts, and finally seat).
If really need be, I can pull seat out this weekend for proper photos. Car is in an awkward spot to do so during the week.
I've also got a spare of the pre-made brackets since I never used the drivers side one if you would like it.