So, here’s the guitar with the broken neck repaired and refinished.
To summarise the repair, the break had been repaired before by another repair shop so I had to make sure all old glue residue was removed.
The neck was then glued, reassembled and clamped up for a couple of days.
Then I routered 2 channels through the break at 90 deg to it and on either side of the truss rod. I then made a pair of mahogany splints and glued them into the channels to strengthen the repair. I trimmed these down and sanded them into the neck profile, coloured the repair area, lacquered it and gave it a final rub down and polish.