'91 735ia wife drove without water, no compression

[oski10]

I have a '91 735ia. The radiator sprung a leak and my wife drove the car for about 7 miles to get off a bridge. The mechanic said along with the new radiator the car has no compression. I plan on replacing the radiator my self and I am contemplating tearing apart the head or having a mechanic do it.

What is the likely hood that I will need to replace the whole head vs just the head gasket? I have heard these heads warp easily. Have people had good success grinding the head using the thicker head gasket. Any "land mines" I need to look out for? Any "while I'm at it I should replace...." Thanks for your help.