Spark Plugs, Engine Shake??

[Phillyfanfrombirth]

Yeah... if it ran alright before, but runs poorly now, I'd say it is either a crossed wire or a bad set of wires that are now touching each other.

As far as the oil/carbon... some of that could be as simple as a bad plug or wire or bad gap on #5....

7 and 8, well, oil in the combustion chamber is never a great sign. The hope would be that it is minor and a better quality plug might do the trick in burning that off rather than letting it accumulate...

One of the things that I like to use for cleaning that stuff up, it especially works well on fuel injection engines, is Valvoline SynPower Complete Fuel System Cleaner... I've seen the stuff work wonders when I was running out of ideas, and if your engine has already seen its best days, it might be something to check out.