I feel your frustration when presented with a failure which management doesn't allow to be repaired properly. A cyl head should always be checked when replacing a head gasket- but what do we know?

If you're going to reuse the block- make sure you to check the flatness of the block where it meets the head. I have seen these warp as well right at the coolant passageway.

I have had custom head gaskets made (Cometic gaskets Inc) which have worked out well for troublesome engines. Combining the thicker gaskets w/ thicker head bolts (non- stretch to yield) has worked well on a couple of older units I service.