The next part of the electrical sort-out was the panel in the engine bay. The one with the CDI box, rectifier, couple of relays, "speed switch" etc.
Here's what came with the car:
Today it looks like this, which is quite nice but not the interesting part....
The interesting (to me) part is that I'm using a CDI+ box, having enjoyed good results with the one in my 69 car. The CDI+ is a CDI box replacement from www.classicretrofit.com; modern digital electronics and programmable ignition curve. I went for the Stealth version, built into a Bosch original case. I'm going a step further this time and locking the distributor, so the CDI+ is responsible for the advance curve.
For my car, the distributor is a Bosch 007. Standard advance curve for that is:
It's pretty easy to get the same curve into CDI+, as a starting point:
Please ignore the deliberate mistake - I've gone beyond the available adjust room for the amount of initial physical advance (hence my curve goes into the red area of the graph). I took the screenshot before I'd finished fiddling about.
Note also a few useful bells and whistles. On my other car I particularly like the soft limiter - much more civilised than the all-or-nothing mechanical limiter (spring in the rotor arm).