I was able to repair all wires until I came across two wires with the exact same colour and size, blue with a thin red stripe.
Front#1: 12V on ignition, no markings
Front#2: No power on ignition, gold text marking
Rear#1: Leads to fuel pump, no markings
Rear#2: Leads to ???, gold text marking
So going with my best judgement, I joined Front#1>Rear#1 and Front#2>Rear#2, and tried starting it up.
Unfortunately I had been charging the battery and manged to put it back in the wrong way round

So I replaced the fuse and tried again. On ignition, a yellow light above the fuel gauge came on, seems it a rear window demister (Car doesn't have one

When Front#1>Rear#1 is disconnected, the light goes out. Either way the engine will crank strongly, but not start. I can't hear the fuel coming on on ignition, ever with a stethoscope, although I don't recall ever hearing it in the past.
Any ideas?