Saw this engine on Facebook Marketplace. When the prix came down to $500 (CDN) I couldn't resist... I figure it will be a winter project to keep me busy. 
It will not do a full revolution with a wrench on the crankshaft bolt, it turns till it doesn't. It is possible to turn it back so it is not seized. The seller bought it to rebuild, doesn't know the history and he sold his Boxster so wanted it gone.
I figured it could be a case of piston meets valve and it looks like I was right...
You can see the stub of a broken cylinder 3 exhaust valve on the right.
 
So I'll get that head off soon to see if the engine can be saved. 
There was no glitter in the oil pan and the filter looks OK, I haven't as yet cut the filter open but a quick look didn't reveal anything.
I did find this coil pack...
 
After prying it out I saw this! 
 
A regular spark plug tube is beside it and there is no relation between the two. I understand why it might have leaked.