I built my new wheel today!
It was easier than I expected, it probably took me about 3-4 hours from start to finish. It took a little while to read through my texts on wheelbuilding to refresh my memory of which spokes go where and in what order but I got there. Now it's trued, tensioned, prestressed and appears to be true to within 1mm or so in all three ways (lateral true, radial true and dish).
Going to take it to the bike shop tomorrow for a final sanity check before putting my weight on it but so far it's looking good. I wasn't sure about getting the label on the hub to align with the valve hole, especially given the requirement to turn the hub shell anticlockwise as far as it would go between the second and third sets of spokes, but that also worked out just fine. So it seems to tick all the boxes, even the finnicky cosmetic ones.
Hopefully the sound of my new Hope hub won't annoy me too much, it was a bit of a punt but I wanted something that didn't freewheel silently.