O'reilly's has them as part of their free loaner tool program, if there is one near you.I am almost certain those are cracks in there. Would the oil make that pattern for any other reason?
Would it be worth buying a coolant pressure tester to confirm? There isn't a place here I can rent one from so I'd have to buy one and they're not as cheap as I'd like.
I'm leaning heavily towards option number 3 but that will depend on prices. About how many bones would an L59 crate engine set me back?
A lot of questions, sorry. That's not even close to the amount that's running through my mind right now though...