[Lucky]

Here's what I would do...

1) drain oil into clean container,
2) visually inspect the oil for coolant (also check the coolant tank for any signs of oil),
3) take a powerful magnet and move it around in the oil (especially around the bottom of the drain pan) and see if it pics up any particles, and
4) cut open the filter element and inspect it for any debris.

If you find nothing at all, put in fresh oil and try to fire it up. If you hear bad sounds... shut it off proceed to a tear down. Odds are it will be cheaper to source a new engine off ebay than it would be to rebuild the current lump, but you never know. The tear down may reveal minimal damage.

I recently saw a low mileage S engine on Ebay for $4500. I was tempted to buy it as insurance...