I didn't wait a week like I was going to, so sprayed a couple of coats of polyurethane on the body and neck.First coat was a bit dodgy because it hadn't been thinned enough. Second coat went one nicely. The next day I sanded it smooth. A type S ultra-fine scuff pad (equivalent to the 7448 mentioned by Simon) wasn't quite doing the job, so I had to go with 240 grit to get it smooth. That worked nicely, but does require a light touch. After wiping it down with a lint free micro fibre cloth and some post sanding cleaner, I masked off the timber on the body and neck. Here's the body masked:
And the stripe on the neck done. I continued the stripe around the head, because there was a tiny bit of bleed of the black stain from the front of the head to the side.
On the other side of the neck I replaced the white dots that I painted over with red ones.
The masking of the body is something you need to be patient with and take your time. Also important so that the plastic gets proper coverage to leave a hairs width of the timber showing. Since the red stain is darker than pale plastic, any bits that don't get covered with the stripe will show up looking ugly. .
I did a dry fit of the neck with the hardware installed and a couple of strings.
As you can see it needs some adjustment. The end of the neck lines up nicely with the neck pickup and is very tight in the pocket (it's basically a press fit ). So the question is: Should I hack into the pocket like the guide suggests, or just move the tail across a bit? Even though the tail has a free moving hinge, it turns out that there is no side to side movement within the hinge. It's just too accurately made.
Once that's resolved, the next question is glue choice. Will PVA such as Titebond be good enough, or should I go industrial with boat builders epoxy?