Thanks for all the input. I am going at this slow. So here is a bit more info.
I have driven another fifty miles or so since changing the plugs. It runs just fine. Pulled a couple of plugs tonight and the problem cylinder is already getting grimmy and the other is slightly tan and dry. So the problem was not something simple like a bad plug.
But what was interesting was the puddle of
oil at the spark plug opening. All around it was dry.
Oil only in the spark plug hole. The threads were oily the full length.
I have not yet swapped out the plug wire or looked inside the distributor cap. I may pull the valve cover next to see if there is anything obvious.