Found the cause of the short in the tail lights today. The connection for the number plate lamp wasn’t insulated properly and was touching the floor of the cubby box. The damage that had been done was pretty shocking - behind the dash the wire just got hot, but towards the back the insulation was totally burned away.

The wire had got so hot in the back cubby box it had melted through the loom itself, cutting right through. The big worry here is that the wire has melted into one or more of the others in the loom and caused another short.

I fixed it by running a new cable back from the dash to the cubby box and connecting everything together with spade connectors. Couldn’t get the cable through the chassis - obviously - so I’ve left it hanging loose along the top of the chassis, ready to secure at a later date.

So, now all the electrics, with the exception of the fuel and temperature gauges, are up and running. To celebrate, I lit the drive up and honked the horn a bit!