Here is the story.
Cowl was pulled to check after landing. Mess cleaned up and a run up accomplished. (Sunday)
This is what it looked like after the ground run-up.
The oil at the bottom of the stud / boss was not there before the run-up and there was more oil on the baffle. The suspected crack can be seen in the paint running up from the stud on the boss.
The airplane had the cowl put back on and was tied down for the night. I got ground transportation home.
Since I am an A&P and did not like what I saw, I asked another A&P (Retired US Airway), multi-RV builder, and all around great guy to look over what I saw the next day and give me his opinion.
The next day, we pulled the cowl and use a wire wheel on a drill to clean paint from the area. (Monday) This is what we found:
The gold color stuff is oil. Engine was cold and ran less than one minute.
I did not ask if the airplane should or should not be flown. I would not fly it in that condition.
This is what happened on Tuesday:
Thursday the airplane looked like this:
Saturday, this photo was taken in Mississippi:
It is now Sunday and I am home with the truck and replacement engine.
Some work still needs to be done. I bet someone finds something else wrong in at least one of the photos.