Hey Drewdog, thanks mate 👍, if I knew how much effort was involved I would've looked for an easier option.. But hey, this could be the only mk1 in existence with split fold rear seats !!
These are the side pivot pins which I cut about 10mm out of the cup height and Tig weld it back together after some crude measurements I got it just about spot on

This abortion is the middle hinge, it was from a Hyundai Elantra in USA as couldn't find anything here cheaper. I needed to adjust the hinge pivot point so it was in line with the outer pins so the seats fold down the same and not bind up. I think I got it as good as possible, I was tipping the seat down and up doing minor adjustments until the securing mount does not move, anyway this is the end product..


Seat frame located

Seat folded down, both sides are still welded to keep things straight till it's all ready with the centre hinge

Tomorrow I'll see how far I get, most of it should be lined up and ready to weld brackets and other sundries in place.
Chopping out the floor is a no-go as the floor will be as high as the front fence panel, higher than the tunnel lol so now plan B is to make a copy of the under side of the seat and adapt to the floorpan in some way