Head milling

Got a question...
How can you tell how much has been milled off of a head. I bought mine from a reman company. After I got them I called to find out how much they take off and they could not tell me. They were not even milled flat, I had to have an additional .010 milled to get them flat. Now, I have a coolant leak on the pass side where the block, head and intake meet, right in that corner. THANK GOD IT DOESN'T LEAK INTO THE OIL!!!!!

Thanks guys!
Eric