Thanks to SD Blue's advice and me repeatedly trying, I was able to pop out the lower drain tube with a rope. My initial attempts were with a 1/4" poly rope which was too slick. A similar sized hemp rope popped it right out.

And then I found out some more details. I thought the grommet was OK because it looked OK. Boy was I wrong; it disintegrated. And there was no lower O-ring remaining.

So now I will clean everything up and get ready for reassembly. Of course I have just ordered a new oil pan gasket...put it on the shelf for now.

__________________
Mike Frederick
1986 300SDL, 240K+ miles
1985 300D KaliKar, 270K+ miles