The difference is one wire. You UNGROUND the second field terminal of the alternator you showed in the first photo, and tie that to switched 12V "ignition run" on the key side of the ballast
Difference: Old 69/ earlier VR gets IGN run power, feeds that power to the regulator field which is grounded to control field current
New "flat" 70/ later gets ign power to power regulator. Alternator field gets full switched 12V to one terminal. Green wire now "controls the grounding" coming from VR to control field current