Thanks for your post,

Your car looks great!
Is your Code 265 Mushroom Leather Interior a special kind?

In regards to the head gasket:
At what mileage is it recommended to change it usually and how much labour is involved?

In respects to the wiring harness:
What do you mean "has it been changed or is due?"
I've never had to change a wire harness before in any other car I've owned, so what's the story with this one?
Was there a recall on it ? Is there a new part number? What is the recommended time to change it and what is the labour and cost involved?

By the way, the car is going in tomorrow in for a purchase inspection at the Mercedes dealer which will take about 2 and a half hours.
After the results of the inspection, I will be able to make my final decision.

Thanks