At 105K miles, I'm sure it's due for a cleaning. Any advice...

Going to do spark plugs and wires as well.

Are you getting code P0 400 or P2001?
If not why do anything?

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Did the original plugs installed have anti-seize applied???

I would like to replace them while they are still easy to remove.

Have not checked codes however, I know I have a misfire on #7. Can I swap the coil pack with the adjacent one and see if the miss follows? Or, will I introduce new issues.
Somewhere I read the fuel is shut down on the problem cylinder. I want to make sure I can reset it once I find the problem.
And, I fear damaging the cat converter if I drive it far enough to have the codes read.

I've swapped coil packs 1 and 7 and the miss remained on 7.

Plugs had that 'scary feeling' coming out as if they were seized. Discovered them to be NGKs with the MB logo with the tips are badly eroded. I'm assuming they are original... 105K miles.

Both plug wires on #7 measure approx 2.3K ohms however, one shows to have approx 40K ohms leakage to the metal shield. That would explain the dead #7.

Awaiting parts.