Max, I am in the same boat with my 1985 280SL with a mere 38K on the clock. Since my car is a euro version, my MBZ dealer says, "We will have to work our way through it at $75.00 per hour for as long as it takes." My car passed the high end and failed the idle HC and CO.
I have the distinct feeling that when my car is finished I will be far better off to simply sign the title over to them rather than pay the bill.
Sadly, I have posted requests for help on this site nad have received ZIP!