He now has the wheel back. I striped it, straightened it, spoked up, trued up. Then using the Sheldon Brown method I tensioned all the spokes, then trued again, then tensioned again, then trued again until it stopped being knocked out of true slightly.
Then I went round the rim a few times using the same method to make sure. After that I pushed on the rim round the outside a few times, checked alignment then pushed a few more times.
Spoke tension is pretty even again.
I have definitely done everything by the book this time…