Coolant in 190XT oil pan

A couple of weeks ago. i was baling hay with my 190XT.  When I was finished baling, as I walked by, the right side of the engine was covered in engine oil. Oil level was ok, so I carried it to the house.  When I was checking the tractor, I found the fan belt loose.  My next step was to change the rocker arm cover gasket.  There was a little gob of vaseline looking junk around the vent tube, but no other signs of anything but engine oil.  Once back together, I found the radiator about 1-1/4 gallons low.  I have to add a little water occassionally but usually less than 1/2 gallon.  I went out tonight to get ready to bush hog the pastures. When I checked the oil level  it was slightly above the full standing mark.  It was about level after the gasket change.  I had a funny feeling, so I dropped the oil plug and about 2 seconds of antifreeze came out before the oil.  I HAD a band temp sending unit, but I feel the tractor did not run hot.  There was no steam around the radiator and it felt normal temps while I was checking out the oil leak in the field. Does anyone have any feel as to what I am facing?  Thanks for any advice or suggestions in advance.

Sleeve orings and/or cylinders have pin holes. Complete engine overhaul. May have to sleeve lower bores. Been there, done that. I would stop running it immediately or you might be buying a crank.