what passive pickups did metallica use before they used emgs

[cliff hetfield]

ive heard james used dirty fingers, but not too sure. heavent heard much else on the topic. maybe the 500t??

 

[Nitrobattery]

Dirty Fingers, 500t/496r and Duncan Invaders

 

[Elpelotero]

+1. That's the Kill Em All sound (with a super rare Jose A. Marshall of course)