Hang on Sir! One of the Experienced Techs will get to you Soon. If not Re-Post with “Hello Chrysler Techs, Nordin, Frank, Others X 55hp Help”. I saw your attached pic but could not compare it to my 1970 35hp Chrysler as some that are related.
My guess will be unburned gas/oil draining down from the exhaust. Smell for the presence of gas which might have become excessive due to a carb or fire matter?? If it’s thick w/o a gas smell it might be an issue with the gasket just above your lower unit. I think the oil looked a little high for a L/U issue??
Attach a full view of your motor with the cover off so I can see your carbs or carb and the length of your L/U’s leg. This should show why my 35hp is not related to your 55hp.
Please do not remove a screw on your Lower Unit that is not marked Vent or Drain (when you service the L/U (which I am not seeing). I feel I am seeing the shift fork screw you do not want to pull. As a reminder, I would clean the area and add silicone over it (to hide the Monster).