I have just finished going through an 87 560 SL which had 176 K on it. It was fantastically clean and rust free, but we kept finding things which had to be fixed. The list was long, and some of it really expensive. That is a heavy car, and at those miles all the rubber items from motor mounts, crossmember mounts, steering gear / box, ball joints, and on and on need replaced even if car is well cared for and driven gently. Heat and age do bad things to plastic and rubber items on the engine and they get brittle, leak air, break, etc. The car you describe may very well be worth every dime spent when you finish, but your purchase price is just a place to start the spending. money.