So, onto the neck.
I originally wanted to use the same wood - a long piece of Iroko, but I was a little concerned with how stable it was going to be, so I bought a piece of maple, which isn't super expensive. I think I'll use the Iroko in future but slice it up and laminate it. Having never built a neck before I wanted to make it as easy as possible.
I basically followed a Crimson guitars video and it seems that starting with a decent template is the key. This took a couple of goes and eventually came up with this.
Transferred this onto the maple blank over the centre line and then marked out where the truss rod should be. I'm pretty new to using a router so I had a practice at routing a slot on another strip of wood. Seemed to go ok if I don't try and do too much in one go. The depth stop on the router isn't accurate enough to set and forget, so it seems that plenty of gentle passes is the name of the game.
Set it all up with a conveniently placed clamp to act as an end stop.
I think it took about six passes all told. In hindsight I could have done it with less when I'm more used to it. A little bit of gentle chiselling as the head is slightly wider and voila.
Appears to fit nicely.