So I painted the engine:

http://i.imgur.com/nzP1EE2l.jpg

I had 5 quarts of 10w30 ready for the engine then remembered when I pulled the dipstick there was (old) oil in it. The oil was not surprisingly black. I chucked up a flat head screw driver extension and primed the oil pump. Here's what came out of all but 4 rocker oil holes.

http://i.imgur.com/CfWyujil.jpg
http://i.imgur.com/7Qfmqdol.jpg

This, I assume, is old oil and crud and water? Either way I stopped after too long, knowing I'd need to change the oil asap. What else should I do?

On the plus side, there was very good compression (resistance against the drill) and NO leaks anywhere.