I can see the misfire on # 1 for sure ( bridged gap ).
That greyish fluffy-looking stuff, is ashes that are left over after the burn.
Conventional oil used?
Of course " Gilly " is right about the valve guide seals.
AGE is the killer of them, so is not running the engine, as for example on vehicles that are store for extended periods of time.

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2007 C 230 Sport.