[olddog]

Given what an engine like that is worth, I understand how unsettling it must be to risk serious damage. It is only minor money and time compared to what might happen. A complete freshening up the engine will not hurt anything. I cannot fault your decision.

If it turns out that was just some excess RTV sealant that came off, well so be it. Many a unknown problem was found looking for a non-problem. Good luck, and keep us posted.