I downloaded a generic wiring diagram from StewMac, and set to work. I won't bore you with all the details but I ended up with a pretty neat wiring job.
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Yuh huh, I'm pretty happy with that.
So neck the pickups go in, the neck and middle from the Strat body I got from Mr. Foxen, and the bridge was originally the neck pickup in my old Jag-Stang, so the guitar has a 6.0k bridge pickup as opposed to 5.2k.
Aaaaanyway, I wire up the jack, ground the bridge and set to work using my trusty old Peavey Envoy 110 and a tuning fork (it's much easier to test pickups this way as it means not having to remove brand new strings if you need to do more work), and what I found was a little surprising. Position 1 on the switch was giving me the neck pickup, position two was the neck and bridge combined, and the rest of the switch positions were giving nothing but silence.
So I look at the diagram and check the switch and realise that the wiring on the diagram needs a different switch, so I get yet another diagram and set about desoldering and re-wiring.
And this time it works. Which pleases me.
Now I need to re-string it and set it up left-handed as J injured his hand a while ago and is finding it easier to play left-handed now.
ETA: Oh yeah, and none of the knobs I have will go on the CTS* shafts so I need to get new knobs.
*Yeah, the eletronics are waaay better than needs to be in this guitar, but when there's only about a fiver difference between the generic electronics and the good stuff you might as well just get the good stuff.