I remember our 43 oliver 70 light swith as having a high charge, no lights setting. Maybe the first notch? I remember the gauges as having yellow background but that was almost 50 years ago. The one thing I do know is that the oil pressure was always low when at operating temp. It always ran ok but didn't have much pressure. I would love to have it now to take it apart and find out why the low oil pressure. Cam bearings? Might get a 70 sometime just to play with. Have fun with your 70.