Anyone fitted a four door MK1 Jetta rear seats into a 4 door golf MK1?

I bought some new resit seats to fit to my golf, only after collecting did I realise how much they differ!

Anyone managed to fit these to a golf MK1, or is it a bit involved? So far I think I need to:

Swap out the base and rear bench.
Add a backing to the back rest so the boot contents don't damage the foam.
Work out how to tie the backrest up as the existing seats fold down, but the Jetta seats look like they'd be fixed.
Work out how to attach the parcel shelf to the new rest seats as they lack the anchor point of the existing seats.

Bit more work than I really anticipated!

You would need an old seat frame then attach the new seats/covers to it.