Wiring......
A great challenge to try and understand a wiring diagram - both the layout and the logic.
Electrics have always been a mystery to me, so a very valuable learning curve. Trying to hack the emergency flasher circuit is still a bit hit and miss, but the rest is working okay.
With the rear, I had to splice a 1970 MFI harness into the original SWB harness. The boxes in the back are rather expensive: speed relay, voltage reg, tach adapter, temp time switch, shut-off solenoid, cold-start solenoid etc.
The vital circuits are surprisingly simple (starter, cdi, coil, fuel pump, cut-off). The lighting circuits - particularly to the instruments - seem endless.