Mercedes Benz burning oil

1 quart in how many miles?

I don't know. I just purchased the car and noticed the oil barely touching the dip stick. There is also a note that lights up on the instrument panel that service D is 7000 miles past due. So I am guessing it has been a long time since someone put oil in it.

Ed thank you for your reply. Should the engine need to be rebuilt, what would you estimate the cost to be?

I would figure around 10 grand. Possibly at lot more if you have a dealer do the work.

I would never have 10 grand to fix it. I have a '75 450 slc with a great engine and transmission. Would that fit in this car?

Not in any practical sense. I do not see any reason to panic yet. See how it does once you have fresh oil in the engine.