Ignoring the extra pickup, neither of them conform to the normal 4001 wiring diagram. That's more a Gibson way of wiring the pickups. I'd need to look further, but from the description here https://mixdownmag.com.au/features/g...-cliff-burton/ the switch seemed to just bring in the extra pickup on its own, so its more likely to me that the normal output was fed through the switch so that either the normal or extra pickup output was selected. The extra pickup would have then had no volume or tone control (making it even brighter). But I'm only guessing.