mercedes w210 e300 oil in cooling system

[wardtribe]

I wanted to know if anyone has experienced one way flow of oil into the cooling system at a high rate which is about 1 quart per 100 miles.

History:
1. About 6 months after I purchased the car, I noticed traces of oil in the coolent when I flushed the system. I put 30,000 miles since i have owned the car and it was not building up. I thought a repair was done prior to me purchasing the car.

2. A few months ago oil starting to leak into the cooling system at a rapid rate causing the system to overheat while my daughter was driving the car. I had the head gasket replaced. The head was pressure tested and resurfaced. Also, some valve seals were replaced.

3. The oil leak is still leaking at about 1 quart per 100 miles.

In my understanding there are only 4 things that could be the cause.
1. Bad head gasket
2. Cracked block
3. Cracked head
4. Damaged oil cooler which is attached to the oil filer housing.

My questions to the form are if anyone has heard of a cracked block on a 1996-1999 mercedes E300 and could a cracked block have only oil leaking into the cooling system. It seemls like it should be both ways. With this rate of oil leaking into the cooling system it seems like the leak is occurring at a spot where the oil presure is high.

Thanks in advance for any help.