Well I did get 10.5 installed so SATA does work (it was sold as non booting with a HDD installed).
Only saw 512MB which I fixed by swapping places for the Apple 256MB and aftermarket 1GB modules. Corrosion? Badly seated? Dunno seems to work.

Got a new (NOS?) NIC coming in at 9.99€ which should work.

Quick google suggests that the A1027 can be found in (non US) PowerBooks so I might dig through my pile of spare parts, but not a priority.