The wiring on a Mini is fairly basic- 2 fuses, no relays, lots of earthing points. Which also makes it fairly insane: Fused and unfused power feeds (unfused power is never a good idea), multiple circuits sharing the same 2 fuses, giant switches to handle the loads (or, conversely, switches which are slighty too small to reliably handle the loads required of them).
We plan to re-engineer the wiring loom to modern standards, with relays doing the switching, a separate fuse for every circuit, and modern bullet connectors (which incorporate newfangled concepts like ‘strain relief’, ‘insulation’, and ‘corrosion resistance’). At the same time, we’re hope to retain the old switches, Lucas colour coding on the wires*, and cable routing- essentially making the wiring loom BMC would have made in 1962 if they’d had modern standards.
This might take a while, but to get started here are some pictures of the old loom:
*We might have to be creative with the colour coding. What was the 1963 Lucas colour code for “Seat Heater power feed”?