'98 Legacy Outback blown head gasket? Spark plug analysis, CEL, comp test etc...

[annointed]

I just bought a '98 Legacy Outback Ltd (DOHC EJ25/5mt, 137k miles), with what the owner told me was a blown head gasket (coolant is empty, engine gradually overheats, and the heat blows cold, etc). I plan on using the car to do an EJ257/6mt swap, but first I want to get it up and running in stock form, get it inspected, registered, etc.

At any rate, I just recieved the car from the shipper last week, and my replacement head gasket from subaruparts.com arrived on Monday. Today I pulled the plugs expecting/hoping to find a "steam cleaned" plug or two. Instead, 3 of the plugs look fairly normal, with a considerable amount of charcoal deposit, but nothing really out of the ordinary. But cyl #2's plug is drastically darker, particularly on the threads, on the metal at the base of the threads (where the ratchet/wrench grips to install/remove the spark plug), as well as the upper section of the porcelain extension that the spark plug wires connect to. I took several pics (phone digicam, so forgive the quality) of the plugs that hopefully show enough detail to be of some help.

Anyway, at this point, should I rethink the head gasket problem? It still sounds like the best diagnosis. I noticed the car had a CEL when I drove it the half mile to my house from where I picked it up from the shipping truck. It starts fine and drives smoothly. I have OBD2 software on my Palm, but the Palm's battery just died, so by friday I'll have the new battery to pull the code and see if it sheds any light on possible problems. Until then I don't want to disconnect the negative terminal on the car for any reason, as I would like to see the CEL(s). I also plan to do a compression test to see what kind of results I get. Finally, I'm thinking I should probably just re-fill the coolant, and run/drive the car and see how long it takes for the coolant to drain and/or the temp gauge to rise beyond normal levels, rather than just go on the owner's word that its a blown head gasket.

I should have the pics hosted later tonight, and I appreciate any insight from my fellow nasioc'ers.