Well, I've made some good progress but also had a couple of setbacks.
I dowelled the neck bolt holes because they were in the wrong place and drilled at an angle far from perpendicular to the body, which went well. I then re-drilled them and fitted the neck OK.
I also dowelled the bridge screw holes, because they were also in the wrong place and drilled at strange angles. I suspect that this may have all fitted together with the original neck, but I had to get a replacement because the first one I received had all the frets on the bass side between the 1st and 9th fret filed back way too far. Anyway, I re-drilled the bridge screw holes, and now the bridge and neck fit OK and the strings run reasonably nicely down the neck.
In the meantime, I had also given the body a coat of ebony timber mate, and sanded back. I ended up sanding pretty much all of it off to get rid of all the scratches and machining marks, but I'm pretty happy with it now.
At this point (i.e. after sanding, but before re-drilling holes) I gave it another coat of timbermate, and left it for a few days to let the filler shrink. Unfortunately, when I came back to it, I found that the body has split along the join.
I'm pretty unhappy about that. I'm guessing I can just fill that crack, but how can I be confident that it's not going to reoccur?
I must admit, given that this is supposed to the the "premium" TL kit, I'm pretty disappointed at the moment.
I also started to drill the holes for the string ferrules, and completely failed to get them in a straight line, so I'm going to have to dowel them and start again. I drilled the two end holes through from the front, and then used the bridge as a template for the holes on the back. I just really struggle to get hole position mm perfect with my drill press - the holes for the ferrules are 8mm, so the slightest variation in line or spacing os very obvious. I think I'll dowel them, and then try again with a hand drill.