grease cups on the spindle are empty and I don't know for how long

Cabinet 9A. Both cups on the headstock were dry enough to look painted. I filled them with the grease that was in the cabinet, which is not a sentence I'm proud of. Spindle is quiet. How worried, on a scale from 'oil it and shut up' to 'bearings are already dead.'

If it's quiet and not hot, it was low, not dead. Don't pack them until the grease comes out the ends. A little, often. The stuff in the cabinet is fine if it isn't dried to a crayon.

There's a line in the measure thread about listening to the spindle before you take it apart. You already listened. Write the date you filled them on a piece of tape. Future you will not remember.