I honestly don't think you can get much below 6 pounds EVER with mixing/matching components only (from any era od pARTS).

In fact, I just completed a couple trigger jobs inclduding one UNIT which was from a collector grade HRA that was probably the nicest slickest trigger pull from any stock rifle I have ever run across (at least among those I have worked on). It was right at 6lbs total.

Likewise, I don't rely upon any lubes. done correctly, the trigger should be smooth and crisp dry as a bone (i do leave a little lube on the spring and inner housing to prevent rust).