At this point, you have to pull the distributor and drive, and prime the pump. Turn the ignition on and see if the light goes out.
Did it make any noise? Any doubts, take the sender out and plug a wet gauge in to see what's really going on. Don't start it until it's right.
Agreed. You can tell by the load on the priming drive if you have oil pressure or not. You should also be able to see oil flowing around the distributor gear bushing.
Yep, you will feel it "grab" and pull the drill down once it gets pressure.
I've had a couple of BB's lose their prime for no good reason. Pull the distributor, intermediate shaft and primed them with the drill. No further issues.