Work has continued over the last couple of days with the re-assembly. First the differential was replaced. I ensured the filler and drain plugs were removed (because this would have been an ideal time to "unstick" them if they had corroded in position) and then cleaned up the housing face.
I then coated the face with sealant, lifted the differential into place and bolted it up.
Now the rear half shafts were installed, if you recall I had pressed on the rear wheel bearings earlier in the week.
On one side the old bearing had collapsed which destroyed the oil splash protector. This is a small plastic ring that fits inside the axle shaft and is frequently damaged or lost during bearing issues or bearing changes, it is simply placed inside the axle.
Then I inserted each half shaft and tapped it gently home once the splines had engaged in the diff. The half shafts are retained in place by the brake caliper mounts which bolt around the bearing.
Then the discs are fitted (obviously this would be different if you had standard rear drum brakes). With disks and calipers its a simple bolt on procedure without the faff of setting up shoes and adjusters that come with drums.
Still a way off finishing yet, but at least it feels like its coming back to life now.